Hi Papia,I just thought of a way of doing this without a Fortran compiler. You can use a Type22-Feedback controller, to find the right input that minimizes the error between a set point and a measured signal. In this case, your set point is the heat transfer rate that you want (from Type14), and the measured signal is the result from Type91 (actual heat transfer rate). The control signal from Type22 can be used to modulate (for our purposes, calculate) the mass flow rate that will yield the heat transfer rate that minimizes the error.
I am attaching an example project. The example is very simple. I do not know if in a more complex simulation it may become more difficult to follow this strategy. I will appreciate any comments.
Best regards, Diego David Bradley wrote:
Papia,Type91 calculates the heat transfer rate across the heat exchanger based on the conditions (temperature and flow rate) at the inlets and on the effectiveness specified by the user. The place you need to start is with the 05-Mathematical Description manual to resolve the equations that Type91 uses so that the heat exchange rate is known and some other variable (outlet temperature of one side of the HX for example) is unknown. As Diego and I mentioned in our previous emails, you would then need a Fortran compiler in order to write a new component for TRNSYS.Kind regards, David At 20:32 3/25/2007, papia sultana wrote:Dear Diego, Thanx for your interest.In my problem, I am using 'type 14 h' to read a variable cooling load (let's say within 0 to 24 hr). Next, I am linking this to a 'type 91' HE through anappropriate equation 'equa' (needed to convert the unit). For the HE of 'type 91', I would like to link the 'cooling load' in terms of 'heat transfer rate' in the input list. So that new input list could be: heat transfer rate, hot side flow rate, cold side inlet temp, cold side flowrate. The output list may remain same or could cut down one/ two. My point is, how could I modify the component 'type 91' to cop with variable load?best regards Papia >From: "Diego A. Arias" <daarias@wisc.edu> >To: papia sultana <papia_s@hotmail.com> >CC: trnsys-users@engr.wisc.edu >Subject: Re: [TRNSYS-users] Changing the role of a standard component >Date: Fri, 23 Mar 2007 09:35:30 -0500 > >Dear Papia, > >Changing a component is more than changing the proforma. You need to>change the mathematical formulation, which is done in a Fortran compiler. >If you need to modify a standard component, please feel free to send me a >more detailed description of what you need and I may be able to help you.>Best regards, > >Diego > > >papia sultana wrote: >>Dear TRNSYS users, >>>>I have just started to use TRNSYS for centralized cooling system and I am >>just a novice. I would like to know If I change any of the output variable >>to an input variable or vice-versa to a component, do I need to generate>>new component? If not, I am not able to change any of the variable>>properties from the Proforma dialogue box even after saving the changes?>> >>btw I will highly appreciate If any body like to share a basic central >>cooling model with me. >> >>Best regards >>Papia >> >> > > >-- >Diego A. Arias >TRNSYS Coordinator >Solar Energy Laboratory >University of Wisconsin - Madison >1500 Engineering Drive >Madison, WI 53706 _________________________________________________________________ FREE pop-up blocking with the new MSN Toolbar - get it now! http://toolbar.msn.click-url.com/go/onm00200415ave/direct/01/ _______________________________________________ TRNSYS-users mailing list TRNSYS-users@engr.wisc.edu https://www.cae.wisc.edu/mailman/listinfo/trnsys-users****************************************************************************************Thermal Energy System Specialists (TESS), LLCDavid BRADLEY 2916 Marketplace Drive - Suite 104Partner Madison, WI 53719 Phone: (608) 274-2577 USA Fax: (608) 278-1475 E-mail: bradley@tess-inc.com Web Pages: http://www.tess-inc.com and http://www.trnsys.com "Providing software solutions for today's energy engineering projects"****************************************************************************************
-- Diego A. Arias TRNSYS Coordinator Solar Energy Laboratory University of Wisconsin - Madison 1500 Engineering Drive Madison, WI 53706
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UsingOutputsToCalculateInputs.tpf
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