[Equest-users] Fluid Cooler

[Ron Pecarina]

I am having a problem with a fluid cooler on a project.  The fluid cooler is
a closed circuit cooler that provides heat rejection for a heat pump loop.
I can get the model to run if I omit the heat exchanger which is integral to
the fluid cooler or if I provide a Wet Schedule, but delete the heat
exchanger.  I realize that neither one of these options will give me the
results that I truly need, but it sort of works for some comparative
purposes.  I have also tried this on 3.63 with the same results.

When I run either of the options identified above, I get the following
messages:

 **CAUTION**********************************************************************
             In curve: FluidCooler-FluidCap-fRng&WB     the dependent value
             is exceeding the limits.
             Value/Min/Max/First time:          4.981
0.000          3.000   1/27/16
CURINV: No real root for CURVE:
 1  0.449745  0.027043 -0.000444 -0.028325  0.000285  0.001570

The CAUTION I can get around.  But the CURINV, which relates to the
FluidCooler-FluidCap-fAPP&WB performance curve, typically ends up as
thousands of lines in the output file.  I have yet been able to identify the
cause.

When I add the heat exchanger, the model crashes and I get the following
error:
 ***ERROR*********************
**************************************************
             Heat-Exchanger: FluidCooler-DryHX                has
inconsistent
             input parameters for flow calculations
                   Mode     SupTi     DemTi     DemTo
                      3     39.00     82.00     82.00

The values for SupTi, DemTi and DemTo will vary depending on other
parameters that I may change, but DemTi always equals DemTo.

I have attached the input and pd2 files for the case without the heat
exchanger.  Adding the heat exchanger is simply inserting the Wet Schedule
(Cooler Sch) and using the first Heat Exchanger from the Library.    I
apologize for the size and complexity of the building model, but it's what I
have to deal with.

I also note that the pan losses/pan heater are not accounted for in the
model.


-- 
Ron Pecarina, PE, CEM, LEED-AP
Energy and Sustainable Design Consultants, Inc.
1128 Noblewood Drive
Billings, MT   59101
406-208-0227
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