Absorption Chiller Plant with blank water flow rate field

[BobHenninger]

Helpdesk Ticket 9431

Really need to disallow blank water flow rate field - throw a warning or default to autosize or something. Michael J. Witte on 16 May 2014 10:14 PM

Log of User and MJW comments You cooling towers are also slightly different between the two simulations (capacity specs). Please make the suggested changes in the absorption chiller file and if that still does not work, please send the updated file. Mike

Dear Mike,

Thanks a lot for your help.

I have attached the electric chiller version of the model for your reference. This is a small model of what I am actually doing with a much more complicated building. So any input from you helps.

Regards Amir

On Sat, May 17, 2014 at 2:43 AM, EnergyPlus Support < support@energyplus.helpserve.com> wrote:

I am able to define a chilled water loop using chiller:electric:eir, but when I use chiller:absorption the output has zero cooling. I have tested several examples and the result is the same. I am beginning to suspect the software. Please advise. I have attached a minimal model for your reference.

1. The water flow rates in the absorption chiller were blank. This defaults to zero. Need to put in "autosize".
2. With the chiller autosized, the simulation fails with an overheated condenser loop.
3. The tower is autosizing to zeroes. Not sure why yet.
4. The setpointmanager for the condenser loop (Plant Loop 1) uses the Medium Office ClgSetp schedule. Seems like the wrong values for condenser water setpoint.

Main problem was #1. Perhaps you can figure it out from there. If not, please reply with our fixed idf, and it would be helpful to see the electric chiller version as well (to compare). Mike

Michael J. Witte, GARD Analytics, Inc.

User files esay-compression.idf

[rraustad]

Or simply?:

/required-field /minimum > 0

On 8/20/2014 12:08 PM, BobHenninger wrote:

Helpdesk Ticket 9431

Really need to disallow blank water flow rate field - throw a warning or default to autosize or something. Michael J. Witte on 16 May 2014 10:14 PM

Log of User and MJW comments You cooling towers are also slightly different between the two simulations (capacity specs). Please make the suggested changes in the absorption chiller file and if that still does not work, please send the updated file. Mike

Dear Mike,

Thanks a lot for your help.

I have attached the electric chiller version of the model for your
reference. This is a small model of what I am actually doing with a
much
more complicated building. So any input from you helps.

Regards
Amir

On Sat, May 17, 2014 at 2:43 AM, EnergyPlus Support <
support@energyplus.helpserve.com
<mailto:support@energyplus.helpserve.com>> wrote:

        I am able to define a chilled water loop using
        chiller:electric:eir,
        but when I use chiller:absorption the output has zero
        cooling. I
        have
        tested several examples and the result is the same. I am
        beginning
        to
        suspect the software. Please advise. I have attached a minimal
        model
        for your reference.

     1. The water flow rates in the absorption chiller were blank.
        This defaults to zero. Need to put in "autosize".
     2. With the chiller autosized, the simulation fails with an
        overheated condenser loop.
     3. The tower is autosizing to zeroes. Not sure why yet.
     4. The setpointmanager for the condenser loop (Plant Loop 1)
        uses the Medium Office ClgSetp schedule. Seems like the
        wrong values for condenser water setpoint.

    Main problem was #1
    <https://github.com/NREL/EnergyPlusTeam/issues/1>. Perhaps you
    can figure it out from there. If
    not,
    please reply with our fixed idf, and it would be helpful to
    see the
    electric chiller version as well (to compare).
    Mike

    Michael J. Witte, GARD Analytics, Inc.

User files esay-compression.idf

— Reply to this email directly or view it on GitHub https://github.com/NREL/EnergyPlusTeam/issues/4406.

Richard Raustad Senior Research Engineer Florida Solar Energy Center 1679 Clearlake Road Cocoa, FL 32922 Ph: (321)638-1454 http://www.fsec.ucf.edu/en/

Electric Vehicle Transportation Center http://evtc.fsec.ucf.edu/

[mjwitte]

@rraustad Well, that could work also.

[JasonGlazer]

The test file "easy-compression.idf" in EnergyPlusDevSupport was not the correct file, since it did not use an absorption chiller. I found the original help desk ticket and added the file that did have the absorption chiller called "easy-4.idf". Even after upgrading the file, it still had multiple problems so instead created a new test file called "IndirectAbsorptionChiller_wBlankWaterFlowRate.idf" that demonstrates the problem. During the summer design day, the BIG CHILLER with zeroed water flow rates shows no operation.