Imen, I assume you are using TRNSYS 16 or 17. If so, you can use the PID controller (Type23). Please pay particular attention to the mode setting (parameter 1) and if you use mode zero, set a small time step and make sure that you have some thermal capacitance in your system. Most heat exchanger models ignore thermal capacitance and compute a steady state solution. Without sufficient capacitance in the system (in the form of pipes and tanks), it might be very hard to control the outlet temperature of your heat exchanger. Best, David On 6/27/2010 10:17, imen chraief wrote:
-- *************************** David BRADLEY Principal Thermal Energy Systems Specialists, LLC 22 North Carroll Street - suite 370 Madison, WI 53703 USA P:+1.608.274.2577 F:+1.608.278.1475 bradley@tess-inc.com http://www.tess-inc.com http://www.trnsys.com |