[TRNSYS-users] Heating pipes model

[David Bradley]

Knut Erik,
 Type31 and 709 take an overall UA for losses from the pipe. Where 
Type604 goes a bit farther is to calculate the loss coefficient based on 
some natural convection correlations. I think it also separates out 
convection and radiation and accounts for the thermal mass of the pipe 
and insulation.
Kind regards,
 David


knut.erik.enerstvedt at niva.no wrote:
>
> Jeff,
>
> Thank you for answering my question.
>
> However, I can't seem to find Type 604 in the TESS Hydronics library. 
> Instead, I see that Type 604 is listed among the individual TESS 
> components. Do you think it would be possible to use Type 31 or Type 
> 709 (TESS Hydronics) instead, connecting the "environment losses" 
> output as GAIN in Type 56, or is this a bad idea since I can not 
> separate conective and radiative gains?
>
> Kind regards,
> Knut Erik
>
>
>
> *"Jeff Thornton" <thornton at tess-inc.com>*
>
> 05/12/2009 07:21 PM
> Please respond to
> thornton at tess-inc.com
>
>
> 	
> To
> 	knut.erik.enerstvedt at niva.no, trnsys-users at engr.wisc.edu
> cc
> 	
> Subject
> 	Re: [TRNSYS-users] Heating pipes model
>
>
>
> 	
>
>
>
>
>
> <I need to model heating pipes commonly found in greenhouses. The pipes
> are in loops located 15 cm above the floor, 1 m above the floor, along the
> walls and somewhat below the ceiling. Hot water flows in the pipes and
> heats up the greenhouse. I use Type 56 to model the greenhouse, but have
> not yet succeded in finding a model for the heating pipes. Does anyone
> know an appropriate model for the heating pipes and how to use it in
> combination with Type 56? >
>
> We use the Type 604 model (TESS Hydronics) which accounts for the
> convective and radiative heat transfer to the zone.  Then simply set up a
> new "gain" inside of Type 56 and set the radiative and convective gains as
> inputs to Type 56.  Then make the connections from Type 56 to the pipe
> (zone temperature and effective surface temperature) and from the pipe to
> Type 56 (radiative heat transfer and convective heat transfer).
>
> Jeff
>
>
> Jeff Thornton
> President - TESS, LLC
>
> 22 North Carroll Street - Suite 370
> Madison WI 53703 USA
>
> Phone: 608-274-2577
> Fax: 608-278-1475
> E-mail: thornton at tess-inc.com
> Web: www.tess-inc.com
>
>
> ------------------------------------------------------------------------------------------------------------
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-- 
***********************************************************************
Thermal Energy System Specialists (TESS), LLC 
David BRADLEY                      22 N. Carroll Street - Suite 370 
Partner                            Madison, WI 53703 
                                   USA
P: +1.608.274.2577 
F: +1.608.278.1475
E-mail: bradley at tess-inc.com 
Web Pages:  http://www.tess-inc.com    and      http://www.trnsys.com

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