[TRNSYS-users] Heat Exchanger with Constant Effectiveness

[Jeff Thornton]

<I want simulate a building (type 56)  refreshes by a Canadian well in
using Heat Exchanger. If we used Heat Exchanger with Constant
Effectiveness (type 91) like heat exchanger in the soil. The type 91
requires to fix the value of each flow fluid, or the soil is not a fluid
which poses a problem. why we can resolved this problem? NB: I don't have
TESS library i have just standard library.>

Trying to model a ground heat exchanger in anything other than a model
dedicated to ground heat exchange will very likely fail.  Using Type 91
will not work as it does not account for the capacitance of the soil and
long-term heat build up affects - which can be significant.  The ground
heat exchanger model in the TESS libraries (DST from University of Lund
Sweden) is an excellent model and has been calibrated (with great results)
against several long and short-term data sets.  My strong recommendation
is to purchase the DST model from a TRNSYS distributor and not try and
"trick the system" by using a lesser model.

Jeff


Jeff Thornton
President - TESS, LLC

2916 Marketplace Drive - Suite 104
Madison WI 53719 USA

Phone: 608-274-2577
Fax: 608-278-1475
E-mail: thornton at tess-inc.com
Web: www.tess-inc.com