基于strm-Bell模型的锅炉汽水系统虚假液位特性分析

A study for false level of the boiler steam-water system based on the Astrm-Bell model

锅炉汽包在变工况运行时往往会产生虚假液位现象,严重影响锅炉的安全运行,因此建立复现性较的动态模型来分析虚假液位是十分必要的。本文在2000年Astr(o|¨)m和Bell提出的汽包锅炉动态非线性模型(A-B模型)的基础上对其进行拓展,并在MATLAB/SIMULINK环境下搭建其仿真模型,进行开环验证,然后利用仿真模型进行了虚假液位特性分析,结果表明蒸汽流量、给水流量和热量扰动时均会产生虚假液位,其中蒸汽流量扰动引起的虚假液位最严重,在不同负荷点,蒸汽流量发生相同幅度扰动时虚假液位变化情况不同,低负荷点虚假液位最为严重。

The false water level in boiler drum under varying operating conditions affects the safety of the boiler seriously, thereby establishing a reproducible dynamic model for false water level analysis is necessary. This paper extends the nonlinear dynamic model put forward by Astrom and Bell in 2000, builds a simulation model in MATLAB/SIMULINK environment and conducts the open loop validation, finally analyses the property of false water level. It is verified that the change in steam flow rate, feed water flow rate and heat could cause the false water level, steam flow rate produce the most serious. Meanwhile, false water level varies at different load points of the same magnitude disturbance in steam flow, it is more serious in low-load point.