Re: [TRNSYS-users] Variable flow pump

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

<In a CHSPSS, I have a discharging loop between the seasonal storage and a
heat exchanger. I would like this loop to be run at variable flow, in
order to maintain the output temperature at the set value. What component
(variable flow pump) is best to use and what is the controling
parameter/input (control signal or max flow).>

If it was me, I'd use one of the controlled heat exchangers from the TESS
HVAC library and couple it to the Type 656 variable speed pump model (TESS
HYDRONICS) which is also the Type 110 in standard TRNSYS.  Leave the input
flow rate to the heat exchanger as unconnected and set the initial value
to the maximum pump flow rate.  Then take the control signal output for
the fraction of fluid that passes through the HX in order to maintain the
setpoint and pass it to the pump in order to calculate the correct pump
power.

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