Re: Fwd: Enquiry on Type 4, Type60 and Type 66 modules

[David Bradley <bradley@xxxxxxxxxxxx>]

Dear Howard, 
  We recently completed a project that sounds quite similar to your
proposed system. In it we had two vapor compression cycles and two
storage tanks. Originally we were planning to put both vapor compression
cycles into the same EES file until we found out that it is possible to
use multiple instances of Type66 (my apologies for contradicting Michaël
- if I hadn't tried this last week I would have said that only one Type66
instance was possible as well). We had some trouble getting it to run
initially but found that it was a matter of some simple typos that we had
made, which were causing stragne errors. Initially, we used extremely
simple EES files; each one had only one input and one output. The first
EES file simply added 1 to the input, the other added 2. Once we got that
working, we then started adding the real equations to the EES files. One
other thing that you need to do is make sure that you have a recent
version of EES (within the past few months) because at one point, there
was no way to completely turn off EES warnings about nearly singular
equations and that message was not passed back to TRNSYS. We used tank
models from our own libraries (Type524 specifically). With this model,
one of the parameters is the number of isothermal nodes in the tank. You
can look at the temperature of each node separately and see how well
stratified your tank is. If the flow rates in and out of the tank are
high, then you will see a lesser degree of stratification. Please let me
know if you have any specific questions about the type of errors that you
are seeing. 
Kind regards,
  David

At 01:46 PM 7/9/2003 -0500, you wrote:

From: "Howard" <howardbut@hkusua.hku.hk>
To: <trnsys@relay.doit.wisc.edu>, <bradley@tess-inc.com>
Subject: Enquiry on Type 4, Type60 and Type 66 modules
Date: Wed, 9 Jul 2003 22:07:55 +0800
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Dear all,

Currently I am trying to model a hot water storage tank for storing water heated by a heat pump. There are two similar models, the Type 4 and Type

60 in the TRNSYS and I would like to know:

 

- Any general guidelines to decide which Type of storage tank should be used?

- How do we define the number of stratification? Aren't the stratification is a natural phenomena?

 

On the other hand, I tried to write my own component in EES (such as the compressors, condensers) and would like to add them into the Trnsys project by Type66 module.

However, plenty of error popped up when I started the simulation if two or more Type66 module is used. I sorted out there may be some problem with the data transfer through CLIPBOARD but I cannot resolve it indeed. Does anyone have similar experience before which can share?

 

Regrads,

 

Howard But

The University of Hong Kong

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Thermal Energy System Specialists (TESS)
Jeff Thornton                                   2916 Marketplace Drive
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*********************************************************************************
Thermal Energy System Specialists (TESS)
David BRADLEY                           2916 Marketplace Drive - Suite 104
Project Engineer                           Madison, WI 53719
Phone: (608) 274-2577 USA
Fax: (608) 278-1475
E-mail: bradley@tess-inc.com
Web Page:          www.tess-inc.com

"Providing software solutions for today's energy engineering projects"
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