[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [TRNSYS-users] time delay by means of type 93 (input value recall)




Hello Stefan,

As long as you implement the timestep as a fraction in an EQUATIONS in the control cards, you should be ok. For example,

EQUATIONS 1
TIMESTEP=2/60 !Timestep of 2 mins

Please see the attached for reference.


Best regards,

Matt Duffy


----- Original Message -----
From: "Stefan Wachter" <wachter@mail.hs-ulm.de>
Sent: Fri, April 8, 2011 4:05
Subject: [TRNSYS-users] time delay by means of type 93 (input value recall)

Hello everybody,
 
I am new at trnsys-users.
Currently I`m modeling an already existing solar heating system (for hot water).
In this system the loading pump is activated by a time delay of 4 minutes (after solar pump is launched).
I tried to model this as follows:
 
- simulation time step: 2 minutes
- storage of the control signal of the solar pump over the last two time steps by means of type 93 (input value recall)
- if the control signal of the solar pump is "1" in the stored two time steps, then the loading pump is launched.
 
It works (tried by a simple example deck) but does it also works in context with a quite big deck (120 m² apertur area, 2 continuous controllers)?
I`m concerned about that the small time step of 2 minutes could cause problems (for example oscillations of the controllers).
Could this work or have someone of you another idea how i can solve this problem?
 
Thanks a lot.
Best regards.
 
Stefan Wachter 
 
 
 

_______________________________________________
TRNSYS-users mailing list
TRNSYS-users@cae.wisc.edu
https://mailman.cae.wisc.edu/listinfo/trnsys-users

Attachment: TIMESTEP.jpg
Description: image/pjpeg