MDX61B0008-5A3-4-0T 线性问题
一般来说阀门开度与流量的关系都成平滑的线性关系。如果阀门使用时间长,或者阀门受到损伤,线性就会改变。线性问题可以有多种解决办法,既有参数整定的,也有控制策略的。当然根本的解决办法在于对线性恶化的治理。如果是比较贵重的调速泵线性恶化,难以治理更换,那只好从调节系统寻找解决办法了。
还有个在火电厂中普遍存在的问题:减温水调节阀的线性恶化。这基本上是个顽疾。因为减温水调节阀动作频繁,经常在完全关闭和打开之间反复波动,相当多的电厂减温水阀门线性都很不好,而且还伴随着空行程偏大。两个问题加起来,给自动调节带来很大的困难。
耦合问题
一个调节系统或者执行机构的调节,对另一个系统产生干扰互相干扰,或者是两个调节系统间互为干扰,产生直接耦合。解耦的办法是先整定主动干扰的调节系统,再整定被动系统。也可以在主动干扰的输出乘以一个系数,作为被动干扰的前馈。
还有一种间接耦合。这个现象在协调控制中比较明显:负荷与汽压的关系是互为耦合。解决问题的办法有两种:一种是互为修正前馈,这个解决办法的应用比较普遍,效果不是太好;更有效的办法是整定参数,效果要比前者得多,抗干扰能力也很大,可惜擅长此道的人太少。
MDX61B0008-5A3-4-0T
MDX61B0008-5A3-4-0T
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