[TRNSYS-users] type680 COP_rated

[Ratnalee Patil]

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

www.innovativedesign.net <http://www.innovativedesign.net/> 

 

From: Mehdi Shahrestani [mailto:mahdishahrestani at gmail.com] 
Sent: Thursday, September 15, 2011 10:18 AM
To: 'Emilia Visek'
Cc: trnsys-users at cae.wisc.edu
Subject: Re: [TRNSYS-users] type680 COP_rated

 

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 at cae.wisc.edu
[mailto:trnsys-users-bounces at cae.wisc.edu] On Behalf Of Emilia Visek
Sent: 14 September 2011 20:19
To: Ratnalee Patil
Cc: trnsys-users at cae.wisc.edu
Subject: Re: [TRNSYS-users] type680 COP_rated

 

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 at 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 <tel:%28919%29%20832-6303> 

Fax: (919) 832-3339 <tel:%28919%29%20832-3339> 

www.innovativedesign.net <http://www.innovativedesign.net/> 

 

From: Emilia Visek [mailto:emilia.visek at mail.polimi.it] 
Sent: Tuesday, September 13, 2011 12:14 PM
To: trnsys-users at cae.wisc.edu
Subject: [TRNSYS-users] type680 COP_rated

 

Dear all,

The COPrated from type680, is thermal or electrical COP?

Thank you,

EV

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/trnsys-users-onebuilding.org/attachments/20110915/b54c59b9/attachment-0001.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Type679.pdf
Type: application/octet-stream
Size: 139082 bytes
Desc: Type679.pdf
URL: <http://lists.onebuilding.org/pipermail/trnsys-users-onebuilding.org/attachments/20110915/b54c59b9/attachment-0001.obj>