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Dear Mehdi, I agree with you – Type 680 is a mystery; a comment from David/Matt/Jeff
would be appreciated. Type 107 – the hot water fired single effect
chiller was written in 2001, later edited in 2004; but the discussion on Type 680
I found on the web is much later. Wonder what the differences are between these
two. In any case, I do not have Type 680 in my TESS library either. On the COP issue - just to clarify: there are two COP terms in
the nomenclature of the absorption chiller documents – (i) COPRated
& (ii) COP (for the device). (i)
The rated COP (used in equation 679.4) that we supply to the
model as a parameter is just thermal as you said. I have highlighted in the attached
document for steam-fired chiller as an example. (ii)
However, the model calculates the actual COP of the device based
on equation 679.9 & provides as an output. As per the documentation, this
COP value considers the QAux. I also confirmed that the code matches
the documentation. CALCULATE THE RESULTANT COP OF THE MACHINE IF((QAUX+QSTEAM).GT.0.) THEN
COP=QCHW/(QAUX+QSTEAM)
ELSE
COP=0. Regards, Ratnalee Patil B.Arch., M.A.Sc. Engineering Sustainable Design Analyst Innovative Design 850 West Morgan St. Raleigh, NC 27603 Ph: (919) 832-6303 Fax: (919) 832-3339 From: Mehdi Shahrestani
[mailto:mahdishahrestani@gmail.com] Dear Emilia First of all, I could not find type 680 in TESS. Any way all the models of absorption chillers have some similar
approaches. It means that the cop exactly is the provided cooling divided by
used heat. Please be aware that in the Qaux is not taken into account in the
cop equation (as it should not be considered based on the open literature). I checked this through the Fortran code of Types 676 to 679 and
107. You can do the same. Also you can find it in TESS documentation related to
each type. But the question is still unsolved that TESS ver 17 does not have
type 680! Hope it helps Mehdi From:
trnsys-users-bounces@cae.wisc.edu [mailto:trnsys-users-bounces@cae.wisc.edu] On
Behalf Of Emilia Visek Dear Ratnalee, Thank you for the explanation. I believed
so, but it was not clear from TRNSYS documentation. The type680 si located in HVAC TESS library
under single-effect absorption chiller hot-water fired. Best regards, Emilia Visek On Wed, Sep 14, 2011 at 8:48 PM, Ratnalee
Patil <Ratnalee@innovativedesign.net>
wrote: Emilia, For the absorption chiller models I
believe the rated COP to be supplied as a parameter is thermal COP (Qcooling
output/Qheat input to generator). In the COP output from the
chiller model however, the electricity consumed by the chiller for the
operation (for pumps etc.) is taken into consideration based on the auxiliary
electric power (Qaux) supplied as one of the parameters. Thus the
output COP = Qcooling output/(Qheat input to generator + Qaux).
By the way, where is this Type 680
located? I am aware of Types 676 to 679, Type 681, and Type 107 for absorption
chillers. Thanks. Regards, Ratnalee Patil B.Arch., M.A.Sc. Engineering Sustainable Design Analyst Innovative
Design 850 West Morgan St. Raleigh, NC 27603 Ph: (919) 832-6303 Fax: (919) 832-3339 From: Emilia
Visek [mailto:emilia.visek@mail.polimi.it]
Dear
all, The
COPrated from type680, is thermal or electrical COP? Thank
you, EV |
Attachment:
Type679.pdf
Description: Type679.pdf