Could you use an equation instead of
changing the fortran code? Something like (CW greater than 24C) AND (HW less than 85) AND (Tset less than 7) THEN (control
signal = 0)? Equations are useful for quick fixes if you don’t want to recompile
the fortran type.
Marcus
MARCUS JONES, MSc
Energy Department
Sustainable Building Technologies
Bitte beachten Sie unsere neuen Kontaktdaten!
Please note our new contact details!
AIT Austrian Institute of Technology
Österreichisches
Forschungs- und Prüfzentrum Arsenal Ges.m.b.H.
Giefinggasse
2 | 1210 Vienna | Austria
T
+43(0) 50 550-6387 | M +43(0) 664 210 24 15 | F +43(0) 50550-6598
marcus.jones@ait.ac.at |
http://www.ait.ac.at
FN: 165088b HG Wien | UID: ATU46577208 This email and any attachments
thereto, is intended only for use by the addressee(s) named herein and may
contain legally privileged and/or confidential information. If you are not the
intended recipient, please notify the sender by return e-mail or by telephone
and delete this message from your system and any printout thereof. Any
unauthorized use, reproduction, or dissemination of this message is strictly
prohibited. Please note that e-mails are susceptible to change.
Österreichisches Forschungs- und Prüfzentrum Arsenal Ges.m.b.H. shall not be
liable for the improper or incomplete transmission of the information contained
in this communication, nor shall it be liable for any delay in its receipt.
-----Original Message-----
From: Jeremy Osborne
[mailto:j.osborne@student.unsw.edu.au]
Sent: February 8, 2010 7:08 AM
To: trnsys-users@cae.wisc.edu;
techsupport@tess-inc.com
Subject: [TRNSYS-users] dynamic
data invalid data points
Dear
All,
I am modeling a BROAD single effect absorption chiller using type680. This uses
the catalog data lookup approach. Not all data points are available for all
operation conditions, for example, with cooling water (CW) in of 30C, Set point
Temp 7C, and hot water (HW) input of 85C there is no capacity data point
because it is below 50%, however there is a data point available at CW of 24C,
set point temp of 7C and HW input of 85C so we need to have the 85C included in
the data file.
The problem is what to put as the data point in these invalid points?
Zero (0) works for most, as it just turns the chiller off, but a problem
occurs when the conditions are between an invalid and a valid data point
because the dynamic data point interpolates between the 0 and the real value
leading to unrealistic data.
There needs to be a way to switch the chiller off when an any invalid data
point is used.
One solution is to add another 0, Zero point very close to each side of the
point, for example(not exact), do 85, 89.9, 90..... = capacity 0, 0,
0.74.....
This would minimize the interpolation chance, however not great and pointful to
create the data file.
Another solution would be to put NA or something in the data file for the
invalid points, and change the fortran code to recognize this and switch the
chiller off. Similar to the errorif function in Excel.
However my fortran is very limited and i couldn't find anything on the web.
Has anyone found a better solution or can help with this?
Kind regards,
Jeremy