Re: [TRNSYS-users] Questions on the Vertical U-Tube GroundHeat Exchanger

["Jeff Thornton" <thornton@tess-inc.com>]

<Otherwise, it is not possible to model a double U tube heat exchanger
with this Type557. >

That's not true at all.  Type 557 can easily model more than one u-tube
per bore.  Parameter 11; negative of number of u-tubes per bore can be set
to -1, -2, -3 etc to represent 1,2,or 3 u-tubes per bore.  The DST wizard
- which is just there to make things easier for most applications - also
has a parameter for the number of u-tubes per borehole.

The reference flow rate is the flow rate that each "pipe" will see and is
used to calculate the internal convection coefficient.  So if the flow
rate is 1000 and you have have 5 boreholes in series and 1 u-tube per
bore, then the reference flow rate would be 1000.  If you have five
boreholes in parallel and two u-tubes per bore, then the reference flow
rate would be 100 (10 parallel flow paths).

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@tess-inc.com
Web: www.tess-inc.com