Jose,
You are correct that the inlet flow rate to 637 and to 536 in the chosen modes set their respective flow rates. But without any pipes or a tank or something to provide some capacitance to the loop as you find in a real system. I'm guessing that you are getting into convergence issues. Try a small timestep and some thermal mass (pipe, tank, etc) to see if it eliminates the problem. Also make sure you have the control mode set correctly for the collector. Are you setting a fixed temperature for the collector or one that is a function of the inlet temperature (ie a fixed temperature rise).
Jeff
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Jeff Thornton President - TESS LLC 3 N. Pinckney Street, Suite 202, Madison WI USA 53703 Office: (608) 274-2577 Fax: (608) 278-1475 www.tess-inc.com E-Mail: thornton@tess-inc.com
On 03/26/2019 10:39 am, José María Roca via TRNSYS-users wrote:
Hi community, hope everyone is well.I’m trying to model steam generation from solar parabolic trough, so to achieve this I have connected a type 536 outlet to the inlets of the counterflow HRSG type 637a.The T536, is set to vary the flowrate to try and reach specified outlet temperature, so the flowrate is set by this component and in turn the input flowrate isn’t used. Right?The T637a calculates the maximum steam flowrate available from the inputs and restrains, so this component sets the steam flowrate, ans so the input of steam flowrate isn’t used. Right?I have the resumed the main connections to:T536: Outlet flowrate —> T647a: Input hot side flowrateT536: Out temp —> T647a: In hot tempT637a: Out hot flow —> T536: in flowT637a: Out hot temp —> T536: In tempT637a: Out steam flow —> T637a: In steam flow (continuity?)This will produce a 441 message "The inputs to the listed units have not converged at this timestep. The values at the last iteration will be used and the simulation will proceed…” units are identified to the collector (T536) and HRSG (T637a).If I delete the 637a or the 536, the error 441 disappears, so this points that there is a problem with the connections or information exchanged between them.Where should I start checking?Best,José María Roca
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