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<p class="MsoNormal"><span lang="EN-US">Hi,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">I have been programming a log gasification boiler based on its behavior in reality. Unfortunately I have trouble calculating the right mass flow and the outlet temperature.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">In praxis, the mass flow changes and is variable. But the same goes for the outlet temperature. It increases with time. Since they are dependent on each other (Q = m*cp*deltaT -> m = Q/(cp*deltaT)) I can’t figure out
how to correctly calculate m and T_out.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">A little about the boiler and system: <br>
It has a nominated power and a part load ratio and switches off, when the outlet fluid temperature reaches a certain point. So you could say, the amount of energy transferred to the fluid per time is fixed. The boiler is connected to a storage tank and the
fluid entering the boiler (coming from storage tank) is tempered with the outgoing fluid so that T_in has a minimal temperature of 65°C.
<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">I now have two unknowns, m and T_out (and three know, Q, cp and T_in). Since in praxis they both vary, I can’t say that one is fixed, at least not completely. I tried setting some boundaries with a minimal and maximal
mass flow but I couldn’t figure it out. <o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Is there a way, type or solution of any kind, where TRNSYS calculates an optimal mass flow/outlet temperature for the system?<br>
I feel like I’m forgetting about or missing something essential to all of this. <o:p>
</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Thanks a lot for any help!<br>
<br>
Best regards, Jan<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">(if needed I can provide the F90 file for the boiler, it’s jus not very clean and I don’t know if it really helps)<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><img width="569" height="215" style="width:5.927in;height:2.2395in" id="Grafik_x0020_1" src="cid:image002.jpg@01D85E40.399D2EF0"><span lang="EN-US"><o:p></o:p></span></p>
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