Author Topic: Storage place, avoiding negative stocks  (Read 16596 times)

Offline vnorberg

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Storage place, avoiding negative stocks
« on: August 05, 2015, 10:23 »
Good morning,

I am sitting and trying to model the use of a CHP plant in my process, where I managed to collect the electricity and heat overflow in a storage place. Now I would like to use this waste el. and heat to minimise the total demand from the CHP plant. This I need to do at each process where the el. and heat is needed. However, at some point is the storage at an end and at that point, I receive the warning "negative stocks are not allowed". How do I assign the storage a variable that cannot be <0?
In my user defined functions I have to assign how much I want from the waste storage but I cannot see the present amount of the storage.
E.g. Heat from CHP=Heat demand for process - waste heat from CHP*IF(waste heat from CHP >0)

Thank you for your consideration,

Victor Norberg