基于CMAC算法的锅炉汽包非稳态水位安全动态矩阵控制

摘要:

由于锅炉启停过程中,汽包内部的蒸汽接触形成的温差增加了锅炉的受压缩应力和拉伸应力,使得汽包的非稳态水位产生超调或振荡,导致水位的波动范围较大。对此,提出基于CMAC算法的锅炉汽包非稳态水位安全动态矩阵控方法。引入CMAC预测算法预测动态锅炉汽包水位变化趋势。通过设计目标水位参考轨迹实现时滞补偿,以避免水位超调或振荡。采用动态矩阵,使优化控制量后的时滞汽包水位与无时滞汽包水位完全相同,实现水位输出误差的优化控制。测试结果表明,设计方法在锅炉处于稳定负荷运行状态,蒸汽流量和给水流量保持不变的工况下,能够将汽包水位维持在设定值附近,且波动范围小,有效实现了水位稳定。

Abstract:

Due to the temperature difference formed by the steam contact inside the steam drum during the boiler start stop process, the compression stress and tensile stress on the boiler are increased, causing the non steady state water level of the steam drum to overshoot or oscillate, resulting in a large range of water level fluctuations. A dynamic matrix control method for non steady state water level safety of boiler steam drum based on CMAC algorithm is proposed. Introduce CMAC prediction algorithm to predict the trend of dynamic boiler drum water level changes. By designing a target water level reference trajectory, time delay compensation can be achieved to avoid water level overshoot or oscillation. By using a dynamic matrix, the delayed steam drum water level after optimizing the control variable is made exactly the same as the non delayed steam drum water level, achieving optimal control of water level output error. The test results show that the design method can maintain the steam drum water level near the set value with a small fluctuation range, effectively achieving water level stability when the boiler is in a stable load operation state and the steam flow rate and feedwater flow rate remain unchanged.