[BLDG-SIM] Closed circuit cooling tower in DOE2.1E

Konstantin Babets babetsk at jbb.com
Wed Mar 24 07:27:20 PST 2004


 
Mike, thanks for the promt response.

 

We do not use any front end, and deal with BDL code. I was just surprised to see no explanation of a "closed-twr" keyword in any of the manuals. It just does not look like there is a provision to account for spray water requirement, additional pumping energy, etc.





Konstantin

  ----- Original Message ----- 
  From: mbusman at noresco.com 
  To: babetsk at jbb.com ; BLDG-SIM at gard.com 
  Sent: Wednesday, March 24, 2004 9:52 AM
  Subject: RE: [BLDG-SIM] Closed circuit cooling tower in DOE2.1E


  Konstantin,

  What front end are you using to insulate you from having to deal with text at the BDL level?  Our office has been using Visual DOE for about 7 years now and the central plant editor allows you to specify a closed cooling tower.  Anyway, I did a quick sample run specifying a low efficiency (as noted by the high approach) closed tower and the BDL text the program wrote looks something like what I have below.  If your GUI front end doesn't allow a closed tower, you might have to roll up your sleeves and insert similar text into the input file.  Make sure to change parameters as appropriate.

  Good luck.

  Mike Busman
  NORESCO, LLC

       *3143 * $Cooling Tower

       *3144 * TOWER0 = PLANT-EQUIPMENT

       *3145 *   TYPE = CLOSED-TWR

       *3146 *   SIZE = -999

       *3147 *   INSTALLED-NUMBER = 1

       *3148 *   MAX-NUMBER-AVAILABLE = 1

       *3149 * ..

       *3150 *  

       *3151 * PART-LOAD-RATIO

       *3152 *   TYPE = CLOSED-TWR

       *3153 *   ELEC-INPUT-RATIO = 0.0081

       *3154 * ..

       *3155 *  

       *3156 * PLANT-PARAMETERS

       *3157 *  

       *3158 *  $Electric Compression Chiller

       *3159 *   OPEN-CENT-COND-TYPE = TOWER

       *3160 *   OPEN-CENT-UNL-RAT = .1

       *3161 *  

       *3162 * $Compression chiller('s) condenser and evaporator water flow

       *3163 * $ includes evaporator flow for two-loop systems.

       *3164 *   COMP-TO-TWR-WTR = 6

       *3165 *   CHILL-WTR-T = 44

       *3166 *  

       *3167 * $Fuel Hot Water Plant Boiler.

       *3168 *   HW-BOILER-HIR  = 1.666667

       *3169 *  

       *3170 * $Tower

       *3171 *   TWR-DESIGN-APPROACH = 20

       *3172 *   TWR-DESIGN-RANGE = 10

       *3173 *   TWR-DESIGN-WETBULB = 78

       *3174 *   TWR-SETPT-CTRL = FIXED

       *3175 *   TWR-SETPT-T = 85

       *3176 *   TWR-THROTTLE = 10

       *3177 *   MIN-TWR-WTR-T = 66

       *3178 *   TWR-CAP-CTRL = ONE-SPEED-FAN

       *3179 *   DIRECT-COOL-MODE = NOT-AVAILABLE

       *3180 *   $ Condenser pump includes a weighted average including all

       *3181 *   $ the evaporator and condenser pumps for water cooled chillers

       *3182 *   TWR-PUMP-HEAD = 10.0

       *3183 *   TWR-IMPELLER-EFF = 0.77

       *3184 *   TWR-MOTOR-EFF = 0.9

             *3185 *  

    -----Original Message-----
    From: Konstantin Babets [mailto:babetsk at jbb.com]
    Sent: Wednesday, March 24, 2004 6:13 AM
    To: mbusman at noresco.com; BLDG-SIM at gard.com
    Subject: Re: [BLDG-SIM] Closed circuit cooling tower in DOE2.1E


    Thanks to everybody for helping with my river water cooling problem. I found that using hourly output and programming excell spreadsheet was the way to go.

    Here is another problem. How can I approach modeling a closed circuit cooling tower in DOE2.1E?

    Konstantin Babets
    Jaros Baum and Bolles
    Consulting Engineers
    212 530 9455
      ----- Original Message ----- 
      From: mbusman at noresco.com 
      To: babetsk at jbb.com ; BLDG-SIM at gard.com 
      Sent: Thursday, March 18, 2004 12:20 PM
      Subject: RE: [BLDG-SIM] River water cooling


      Konstantin,

      I have become a big fan of the hourly output report capabilities of DOE-2 for presentation purposes, troubleshooting, and to handle situations such as yours where I'm not aware of how to approach the solution within DOE-2.

      You could probably run an hourly report to export systems tons load, CHW supply temperature, and any other variables you might need (CHW pump kW, condenser pump kW, lighting kW, etc.) and dump the 8760 hours of data into an Excel file.  Based on your CHW pump kW, you might want to add a column to account for pump heat to give you total cooling load seen by the chiller.

      Then you need to add 3 columns to calculate from the DOE chiller curve coefficients the multiplier for capacity based on CHW and CW temp. (I assume you have a good idea of the variation in river water temp. by season), multiplier for EIR based on the water temperatures, and EIR-FPLR.  The product of these three values should give you the hourly EIR.  Add another column so that based on the total tons cooling load, you can then calculate chiller kW from the hourly EIR.

      It might end up being a big spreadsheet, but it's really simple in concept to set up and should give you the results you desire.  If you'd like to discuss further, feel free to call me.

      Mike Busman
      NORESCO, LLC
      949-253-3533, ext. 303
        -----Original Message-----
        From: Konstantin Babets [mailto:babetsk at jbb.com]
        Sent: Thursday, March 18, 2004 7:52 AM
        To: BLDG-SIM at gard.com
        Subject: [BLDG-SIM] River water cooling


        Alec, thank you.

        Unfortunately I am using Doe2.1E, where I cannot schedule loop temperatures. BTW, is it possible to write a custom function to access the PLANT?  It does look like I can only use custom functions to modify computations in Loads and Systems. 
        Any ideas?

        Konstantin Babets
        Jaros Baum and Bolles
        Consulting Engineers
        212 530 9455
          ----- Original Message ----- 
          From: Alec Stevens 
          To: babetsk at jbb.com 
          Sent: Wednesday, March 17, 2004 6:02 PM
          Subject: Re: [BLDG-SIM] River water cooling


          Konstantin,
          Not 100% sure, but I think you should be able to schedule the loop temperature.  Create day/week/year schedules and input the appropriate variation in river water temp, use that for loop temp.

          I know you can do this for ground source loop temperature for a WLHP system, so it should be applicable to CW loop.

          just for fun:
          http://www.utilities.cornell.edu/LSC/default.htm

          good luck
          Alec


            ----- Original Message ----- 
            From: Konstantin Babets 
            To: BLDG-SIM at gard.com 
            Sent: Wednesday, March 17, 2004 4:53 PM
            Subject: [BLDG-SIM] River water cooling


            Hello,

            I am working on a project that considers utilizing river water instead of a conventional cooling tower condenser water. Does anyone have an idea how could this be simulated in DOE2.1? (Basically, somehow I need to reset entering condenser water temperature to that of a river water).

            Thank you,

            Konstantin Babets
            Jaros Baum and Bolles
            Consulting Engineers
            212 530 9455
==================
You received this e-mail because you are subscribed 
to the BLDG-SIM at GARD.COM mailing list.  To unsubscribe 
from this mailing list send a blank message to 
BLDG-SIM-UNSUBSCRIBE at GARD.COM

=====================================================You received this e-mail because you are subscribed 
to the BLDG-SIM at GARD.COM mailing list.  To unsubscribe 
from this mailing list send a blank message to 
BLDG-SIM-UNSUBSCRIBE at GARD.COM




===========================
You received this e-mail because you are subscribed 
to the BLDG-SIM at GARD.COM mailing list.  To unsubscribe 
from this mailing list send a blank message to 
BLDG-SIM-UNSUBSCRIBE at GARD.COM
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/bldg-sim-onebuilding.org/attachments/20040324/889b975e/attachment-0002.htm>


More information about the Bldg-sim mailing list