Energy Plus How to Build a "FaultModel:Fouling:chiller" ?

edit

I'm trying to build a "FaultModel:Fouling:chiller" in Energy Plus V8.8. I want to find a result that when chiller condenser fouled, the decrease the "Chiller Condenser Heat Transfer Rate",the increase the "cooling water outlet Temperature",compare to the "Faulty free Model".But there are some weird statement that confuse me. Here are my question:

Question 1 : How to determine the Fouling Factor ? (here is the setting screen - https://ppt.cc/fZN91x) When I am using the "FaultModel:Fouling:chiller" without "Availibility Schedule" and "Severity Schedule", no matter what value I set into the "fouling Factor", the "Chiller Condenser Heat Transfer Rate" is greater than the Faulty free Model . With heat exchangers that have fouling, should the heat exchange be lower? The result is different from the Engineering Reference(P.578) .

Question 2 : How to use the "Severity Schedule" ? (here is the setting screen that severity schedule Value <1 - https://ppt.cc/f4BUPx) (here is the setting screen that severity schedule Value >1 - https://ppt.cc/fTCC4x) When I am using the "FaultModel:Fouling:chiller" with "Severity Schedule" and set the "Fouling Factor" blank. According to the Engineering Reference(P.578) that "The model allows the user to describe the fault using a dynamic fouling factor". I found that when the value in the Schedule is less than 1 , the "Chiller Condenser Heat Transfer Rate" is epual to the Faulty free Model.Then I set the schedule value is greater than 1, the "Chiller Condenser Heat Transfer Rate" is greater than the Faulty free Model. And the "Chiller Condenser Heat Transfer Rate" ratio of the "Fouling" and "the Faulty free" Model is irregular.

Could you do me a favour? Thank you very much