Posted Mon, 08 Jan 2018 09:06:43 GMT by Yohannis Mitiku student
Hi all,

What is a loop breaker? How it works? I couldn't find a document which explains it well.

Posted Mon, 08 Jan 2018 15:32:14 GMT by Enrico Remigi WEST Product Owner
A loop breaker is a special block that [b]breaks an algebraic loop[/b], by introducing a small (negligible) delay between its input and its output

An algebraic loop occurs when a term appears on both sides of an equation.
For instance, the flow balance around a flow combiner for e.g. the RAS recycle is something like:

  [tt]Output = Input + Recycle[/tt]

but the recycle is a function of the output; and therefore:

  [tt]Output = Input + f(Output)[/tt]

which can be simplified to / seen as:

  [tt]O(t) = I(t) + O(t) + other terms(t)[/tt]

Such equation cannot be solved numerically.
By introducing a small delay, a loop breaker allows to rewrite the previous equation as:

  [tt]O(t) = I(t) + O(t-dt) + other terms(t-dt)[/tt]

which can be solved numerically.
Posted Wed, 10 Jan 2018 09:06:02 GMT by Yohannis Mitiku student
Thanks Enrico. It is clear now.

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