Re: [TRNSYS-users] Solar thermal installation and convergence

["John Bisgrove" <jbisgrove@earthsensitive.com>]

Arnaud,

I had convergence problems with single stage pumps in solar thermal arrays. 
Slowing the on/off flow change, or setting a minimum of time the pump stays
on will solve these problems. Adding piping can also help or hurt depending
on the temperatures. (i.e. ground coupling in the winter) To see if the pump
is the cause of your problem, replace the pump with a variable speed pump
(don't worry about power curves) and assign a linear control as function of
temperature. 

Good Luck

John Bisgrove
Earth Sensitive Solutions
7523 County House Road
Auburn, NY 13021
(315)253-3779

-----Original Message-----
From: A.Thome-08@student.lboro.ac.uk [mailto:A.Thome-08@student.lboro.ac.uk]

Sent: Sunday, August 23, 2009 5:11 PM
To: trnsys-users@cae.wisc.edu
Subject: [TRNSYS-users] Solar thermal installation and convergence



Good evening everyone,

I am modelling a solar installtion where the water tank has two heat
exchangers (solar panels and gas boiler).

When I run the simulation, I have many "warning". Therefore, I increased the
number of warning allowed. However, the simulation still does not go
throught and I do not manage to understand why?

In my model, I used the type 60e which have its own "fraction of critical
timestep". I set it to the minimum: 1. Even doing that, I still do not
manage to make the installation work.

Does anybody could help me?

Thank you very much.

PS: I put the .tpf file attached.

Arnaud