[TRNSYS-users] Problem with psychrometrics in type 51b

[Jeff Thornton]

<I'm trying to simulate a solar powered air conditioning system which has
an absorption chiller. The problem is that when i start the simulation
,error manager stops it immediately and informs that "The utility routine
PSYCHROMETRICS, which calculates the thermodynamic properties of moist
air, has been called with a wet bulb temperature above the maximum wet
bulb temperature for the given pressure.Please check the routine which
calls the PSYCHROMETRICS routine for possible sources of errors.   
Reported information :error 114.". The problem is related to the cooling
tower (type 51b). Does anyone have any tips or ideas about what should i
do or where should i focus on? >

Use the TRACE feature and see what inputs are being sent to the cooling
tower model - that way you can see if the simulation is "running away" and
forcing the fluid temperatures way up.  Many times in this situation users
have a large timestep, loose tolerances and no capacitance in the closed
cooling tower loop and the simulation cannot find a stable solution...

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