关键词: 氨法脱硫, Smith预估器, 模糊算法, 延迟时间, 实时跟踪控制, PID参数整定, 脱硫系统, 纯滞后环节

Abstract:

The ammonia desulfurization system has the problems of large lag, nonlinearity and poor real-time load tracking. Smith predictive controller has been designed to solve these problems, which improves the real-time performance of the system by compensating the delay time. However, the PID parameters of system are always set by cut-and-try method, which results in poor stability of the system. In this study, a fuzzy PID parameters adaptive adjustment method is proposed. The adjustment values of parameters of the PID controller are obtained by the fuzzy algorithm, and the PID parameters are adjusted adaptively, so that the SNOx concentration is controlled near the preset value. Different from the traditional step signal judgment control effect, the proposed method uses real-time load data to simulate the model, and the data simulation results prove the feasibility of Smith calculation fuzzy PID controller. When the system is stable, the error between SNOx concentration and the preset value is within 0.5 ppm, and adjustment time is greatly shortened. These results show that the proposed method improves the real-time tracking performance of the ammonia desulfurization control system, and realizes the fast, accurate and stable desulfurization control performance.

Key words: ammonia desulfurization, Smith predictor, fuzzy algorithm, delay time, real tracking control, PID parameter tuning, desulfurization system, pure lag link