[Equest-users] Performance Curves - independent variable boundaries

Jones, Christopher Christopher.r.Jones at wsp.com
Fri May 17 09:10:21 PDT 2019


Follow-up questions:
If you specify the OUTPUT-MIN and OUTPUT-MAX will eQuest still through the CAUTION?

If you specify DIAGNOSTIC WARNINGS .. will eQuest still through the CAUTION?

Also where do you specify the DIAGNOSTIC keyword in the eQuest interface? I sometimes find it useful to specify DIAGNOSTIC DEFAULTS to see what hidden defaults might be leading to the results I am seeing. I know I can go through the BDLKEY.OUT and BDLDFT.DAT files to check the defaults but I don't always find what DIAGNOSTIC DEFAULTS prints in the .bdl file.



Christopher R Jones, P.Eng.
T+ 1 416-644-0252

[cid:image002.png at 01D50CA9.7DF12660]

From: Equest-users [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Bishop, Bill via Equest-users
Sent: Friday, May 17, 2019 11:33 AM
To: 'Phil Jordan' <phil.jordan at clearesult.com>
Cc: equest-users at lists.onebuilding.org
Subject: Re: [Equest-users] Performance Curves - independent variable boundaries

Hi Phil,
Good question! When a performance curve uses Raw Data Points (INPUT-TYPE = DATA), the coefficients for the curve are generated based on the data points and can be seen in the eQUEST Basic Specifications tab for the Performance Curve Properties. (You can generate the coefficients yourself mathematically, by using the LINEST Excel function for example.) Outputs for the curve will be determined even if the inputs (independent variable values) are outside the range of the raw data points. For example, a PLR of 0.2 and dT of 25F gives an EIR multiplier of 0.14 in the example curve below. The outputs could even be nonsensical if the simulation used garbage inputs. (An output of -0.2 using inputs of -1,-1.) I don't think there is a keyword that restricts the input variable values, but the OUTPUT-MIN and OUTPUT-MAX fix the output at those values rather than letting it go outside of those boundaries. Additionally, chillers have the MIN-RATIO keyword which defines the load for which the chiller will cycle on and off.

Regards,
~Bill

William Bishop, PE, BEMP, BEAP, CEM, LEED AP
Senior Energy Engineer

[Pathfinder-EA-logo-2]T: (585) 698-1956                        F: (585) 325-6005
bbishop at pathfinder-ea.com<mailto:wbishop at pathfinder-ea.com>        www.pathfinder-ea.com<http://www.pathfinder-ea.com/>
134 South Fitzhugh Street
Rochester, NY 14608               [cid:image008.png at 01D50CA9.51C6D850]   Act on the climate crisis - the Energy Innovation and Carbon Dividend Act

From: Equest-users <equest-users-bounces at lists.onebuilding.org<mailto:equest-users-bounces at lists.onebuilding.org>> On Behalf Of Phil Jordan via Equest-users
Sent: Thursday, May 16, 2019 7:54 PM
To: equest-users at lists.onebuilding.org<mailto:equest-users at lists.onebuilding.org>
Subject: [Equest-users] Performance Curves - independent variable boundaries

When a curve output exceeds the limits (min/max output, OUTPUT-MIN and OUTPUT-MAX keywords), eQUEST throws a CAUTION message in the SIM file, something like this:

**CAUTION**********************************************************************

             In curve: Variable Speed Drive FPLR        the dependent value

             is exceeding the limits.

             Value/Min/Max/First time:          1.004          0.100          1.000   7/21/ 8




I'm curious, what happens when the input type for a performance curve is "Raw Data Points" and during the course of the simulation one of the independent variables is outside the range of the raw data points? For example, here's a curve from the library (BDLLIB.DAT) that's defined via data points:
$LIBRARY-ENTRY SmFricW3VSD-EIR-fPLR&dT         CURVE-FIT       Sml Fric 3App    -044d2  35
$ 70/140 ton, 3F approach evap & cond; R134a extended 460V  10F superheat       -044d2  36
$ EIR = 0.182, 0.64 kW/ton, COP 5.5                                             -044d2  37
   TYPE = BI-QUADRATIC-RATIO&DT   INPUT-TYPE = DATA                             -044d2  38
   IN-RATIO = ( 1.00, 0.75, 0.50, 0.25,  $ PLR                                  -044d2  39
                1.00, 0.75, 0.50, 0.25,                                         -044d2  40
                1.00, 0.75, 0.50, 0.25,                                         -044d2  41
                1.00, 0.75, 0.50, 0.28 )                                        -044d2  42
   IN-DT    = ( 41.0, 41.0, 41.0, 41.0,  $ ECT-CHW DT                           -044d2  43
                31.0, 31.0, 31.0, 31.0,                                         -044d2  44
                26.0, 26.0, 26.0, 26.0,                                         -044d2  45
                46.0, 46.0, 46.0, 46.0  )                                       -044d2  46
   OUTPUT  = (  1.00, 0.70, 0.46, 0.27,  $ EIR ratio                            -044d2  47
                1.00, 0.66, 0.39, 0.22,                                         -044d2  48
                1.00, 0.65, 0.38, 0.19,                                         -044d2  49
                1.00, 0.72, 0.50, 0.32 )  ..                                    -044d2  50

In the data points, the minimum PLR boundary for the curve is 0.25 - what happens if during the simulation the PLR is 0.20? Does eQUEST use the curve output regardless (and is a CAUTION generated), or is the output at the minimum independent variable used?

Thanks,

Phil Jordan


________________________________


NOTICE: This communication and any attachments ("this message") may contain information which is privileged, confidential, proprietary or otherwise subject to restricted disclosure under applicable law. This message is for the sole use of the intended recipient(s). Any unauthorized use, disclosure, viewing, copying, alteration, dissemination or distribution of, or reliance on, this message is strictly prohibited. If you have received this message in error, or you are not an authorized or intended recipient, please notify the sender immediately by replying to this message, delete this message and all copies from your e-mail system and destroy any printed copies. You are receiving this communication because you are listed as a current WSP contact. Should you have any questions regarding WSP's electronic communications policy, please consult our Anti-Spam Commitment at www.wsp.com/casl<http://www.wsp.com/casl>. For any concern or if you believe you should not be receiving this message, please forward this message to caslcompliance at wsp.com<mailto:caslcompliance at wsp.com> so that we can promptly address your request. Note that not all messages sent by WSP qualify as commercial electronic messages.

AVIS : Ce message, incluant tout fichier l'accompagnant (< le message >), peut contenir des renseignements ou de l'information privil?gi?s, confidentiels, propri?taires ou ? divulgation restreinte en vertu de la loi. Ce message est destin? ? l'usage exclusif du/des destinataire(s) voulu(s). Toute utilisation non permise, divulgation, lecture, reproduction, modification, diffusion ou distribution est interdite. Si vous avez re?u ce message par erreur, ou que vous n'?tes pas un destinataire autoris? ou voulu, veuillez en aviser l'exp?diteur imm?diatement et d?truire le message et toute copie ?lectronique ou imprim?e. Vous recevez cette communication car vous faites partie des contacts de WSP. Si vous avez des questions concernant la politique de communications ?lectroniques de WSP, veuillez consulter notre Engagement anti-pourriel au www.wsp.com/lcap<http://www.wsp.com/lcap>. Pour toute question ou si vous croyez que vous ne devriez pas recevoir ce message, pri?re de le transf?rer au conformitelcap at wsp.com<mailto:conformitelcap at wsp.com> afin que nous puissions rapidement traiter votre demande. Notez que ce ne sont pas tous les messages transmis par WSP qui constituent des messages electroniques commerciaux.



-LAEmHhHzdJzBlTWfa4Hgs7pbKl
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20190517/62c53c22/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image006.jpg
Type: image/jpeg
Size: 9336 bytes
Desc: image006.jpg
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20190517/62c53c22/attachment.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image008.png
Type: image/png
Size: 1554 bytes
Desc: image008.png
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20190517/62c53c22/attachment.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image002.png
Type: image/png
Size: 1860 bytes
Desc: image002.png
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20190517/62c53c22/attachment-0001.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image004.jpg
Type: image/jpeg
Size: 1882 bytes
Desc: image004.jpg
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20190517/62c53c22/attachment-0001.jpg>


More information about the Equest-users mailing list