Emerson Exchange 365

hydrate formation curve in DeltaV

Hi all, I've been tasked with providing an operator alarm when our process conditions are in the hydrate formation region of a hydrate curve but i have no idea how i can achieve this in DeltaV. Ideally i need to enter the curve within deltav, presumably via an x-y plot but i wouldn't know how to generate a digital toggle depending which side on the line our process is on. Does anyone have any experience with plotting curves within deltav that could share some knowledge/ideas on how i can achieve my goal?

• deltav hydrate curve

Stuart Jolley

• 5 Feb 2018 4:14 PM
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2 Replies

• Maarten van der Waal

  

  • 5 Feb 2018 9:20 PM

  The way you describe the challenge is having an x-y plot.
  Is it possible to create a polynomial for the plot?
  If so, you calculate the value of y having x. Then depending on whether the realy is higher or lower than the calculated value you have hydration (yes or no).
  
  You may consider to put the formula in a calc block with a scan multiplier to limit controller loading.

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• MPHymel

  

  • 5 Feb 2018 9:49 PM

  a signal characterizer can be used to set up your x-y relationship. A condition block can then be use to evaluate the output of that block, or you can feed it to your analog PV indication module and use the typical LL,L, H, HH process alarms.

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