Ma Liangyu

Research on fault sample knowledge abstraction and fault fuzzy diagnosis for large power station halving-style condenser

Typical fault sample knowledge library of the halving style condenser is abstracted and completed based on the dynamic simulation model of halving-style condenser developed by the authors. The fuzzy pattern recognition is used to realize halving-style condenser fault diagnosis. A new kind of subordinate function is given to overcome the demerit of one old function. Diagnostic effects of the two different functions are compared by example.

Active disturbance rejection control of once-through boiler unit coordinated system based on pseudo-diagonalization

For the multi-inputs and multi-outputs strong coupling coordinated system of once-through boiler unit, the active disturbance rejection controller of coordinated system is designed based on pseudo diagonalization. Inverse Nyquist array is employed to carry out frequency domain analysis of the model. Pseudo diagonalization is used to design the static decoupling compensation matrix of the system. The dynamic coupling and system unknown parts are observed by extended state observer of ADRC and is compensated to the system. The simulation tests show that, the disturbance rejection results of the load and the main steam pressure for the coordinated control system under LADRC are better than that of PID control.

Model predictive optimal control for the coordinated system of supercritical power unit based on firefly algorithm and neural network modeling

With the widespread implementation of Automatic Generation Control (AGC) in regional power grids, large-capacity supercritical and ultra-supercritical (SC/USC) power units are required to participate in peak load regulation frequently and often operate under wide-scope variable load conditions. Since a SC boiler unit is a MIMO strong coupling system with nonlinearity and large time delay characteristics, the traditional coordinated control strategy based on PID controllers often cannot meet the requirements with slow load response and large steam pressure fluctuations. Therefore, a model predictive optimal control (MPOC) scheme is proposed for the coordinated system control of a supercritical power unit on the basis of an improved firefly algorithm (FA) and neural network modeling. The MPOC scheme is programmed with MATLAB software and implemented in the full-scope simulator of a 600MW supercritical power unit. The test results show that the method can greatly improve the load response speed and keep the main steam pressure within safety limits.

The engineering modular simulation model for circulating fluidized bed boiler unit

The paper introduced the engineering modular modeling method, and developed process simulation algorithms of CFBB (circulating fluidized bed boiler) combustion system with the support of STAR-90 simulation software. The paper also developed a simulation model of DG450t/h CFBB combustion system. The simulation results showed that the model could correctly reflect property of the working process.

Research on drum feedwater distribution style of sub-critical pressure natural circulation boiler

The paper develops a down-comer feed style (DFS) of drum feedwater distribution of natural circulation boiler based on the study of working process in the drum, which can greatly release the drum metal thermal stress by balancing the temperature field of drum wall. The characteristics of the DFS compared to the normally used pressure distribution mode at present are discussed in detail. The paper analyzes the hydraulic characteristics after the down-comer feed style is adopted. It is concluded that DFS is safe on circulation and simple in design, and can be widely used in subcritical pressure natural circulation boilers.