[TRNSYS-users] Blocks in TRNSYS

[fdominguezm at uma.es]

Dear TRNSYS users,

I would like to suggest a new functionality for TRNSYS that I have long
missed. The problem is how to improve the capabilities of TRNSYS to deal
with stiff models, that is, with models that combine slow and fast
dynamics.

The best option would be to implement variable self-adjusting time-steps,
but I guess this would represent a mayor and difficult modification of the
kernel. My suggestion is to implement a structure similar to that of
HVACSIM+. In this program, users can group components by blocks. Each
block is solved with its own time-step. Blocks themselves and interactions
between blocks are defined by the user.

This structure is not always good, but I think it can help to speed up
some models. Currently I have to move any fast dynamics into a FORTRAN
code, in order to be able to solve the rest of the model with a reasonable
time-step.

Hope this will help

Fernando Dominguez Muñoz
University of Malaga (Spain)