Re: has anyone used the type 7 (absorption air conditioner type)?

["Dr.Karl-Christian Rauch" <Rauch-Muenster@xxxxxxxxxxx>]

Hi Windy,

i'm just waiting for an e-mail from an collegue in Hamburg dealing with data

about the Tivoli Storage Manager TSM (IBM/Tivoli) so i saw your question

about the TYPE7 coefficients ...

You have luck that i belong to that people, who can not put away

things from former times.

Please have a look to the work of Jeffrey Clay Blinn (master of Science, Chem.Eng.)

in 1979 at the Uni Wisconsin-Madison powered by the Profs JackDuffie and JohnWMitchell:

Simulation of solar absorption air conditioning, I think this is the original work which

leads to the code of type7.

According to your question about generating the coefficients, here is the answer:

The coefficients aij and bij were obtained by fitting the curves of technical datasheets

for CAPY (steady state capacity of ARKLA WF-36 absorption chiller) and COP (coefficient

of performance of ARKLA WF-36 absorption chiller):

f1(Tg, Tc) = (Rated chiller capacity) * CAPY(Tg, Tc) with

CAPY(Tg, Tc) = a11 + a12*Tc + a13*Tc^2 +

(a21 + a22*Tc + a23*Tc^2) * Tg +

(a31 + a32*Tc + a33*Tc^2) * Tg^2

f2(Tg, Tc) = f1(Tg, Tc) / COP(Tg, Tc)

COP(Tg, Tc) = b11 + b12*Tc + b13*Tc^2 +

(b21 + b22*Tc + b23*Tc^2) * Tg +

(b31 + b32*Tc + b33*Tc^2 ) * Tg^2

Performance data in the data sheets shown as functions of Thw and Tc were converted prior to

functions of  Tg and Tc using

Tg,stst = 0.83*Thw + 0.17*Tc and

Thw = (Tg,stst - 0.17Tc) / 0.83, respectively

Tg generator temperature

Tc condensing water inlet

Thw firing water inlet temperature

The TRNSYS parameter called KAPY controls which pair of coefficients CAPY and COP has been

used during the simulation runtime.

Hope this will help you programming your own chiller.

Best regards

Dr.Karl-Christian Rauch

SAP R/3 Application-Developer

Consultant Tivoli



----- Original Message -----
From: "Windy Hermawan Mitrakusuma" <windyhm@indo.net.id>
To: <trnsys@relay.doit.wisc.edu>
Sent: Friday, November 23, 2001 9:43 AM
Subject: Re: has anyone used the type 7 (absorption air conditioner type)?


> Dear David
> This is coincident with my problem.
>
> I try to modified the type 7, the Yazaki model WFC-7.5, into Yazaki model
> WFC-2.
> I looked to the source code of type 7, then I found that I have to change
> the coefficient of B11 - C33.
> It's sound very easy, but I don't know what the meaning of those
> coefficient and how do I get it from the catalog/specification of WCF-2.
>
> So anybody can explain it to me ?
>
> Thanks and Regards
> Windy H M
>
>
> At 11:32 AM 11/13/01 -0600, you wrote:
> >Anne,
> >   The Type 7 absorption air conditioner model has the advantage that it is
> >pretty easy to use. There are no parameters which will be difficult for you
> >to find. Its main disadvantages are that it models only two specific air
> >conditioner units (the Arkla model WF-36 and the Yazaki model WFC-7.5)
> >which are no longer commercially available. Second, it does not model
> >anything on the rejection or the chilled water side. It simply tries to
> >meet a given load and return the hot water side outlet conditions. I
> >believe that Type 7 also has a built in cooling tower model which cannot be
> >removed without reprogramming.
> >
> >There is a series of 6 TRNSYS absorption air conditioner models available
> >for purchase as part of the TESS HVAC library which does model both the hot
> >and cold water side as well as rejection. There is no cooling tower built
> >into the TESS models.
> >
> >Cheers,
> >   David
> >
> >At 01:21 PM 11/13/01 +0100, you wrote:
> >>Dear collegues,
> >>
> >>I would like to know if anyone has ever used the absorption air
> >>conditioner type (type 7).
> >>I would like to know what are its advantages and inconvenients.
> >>
> >>Thank you in advance.
> >>Cordialement
> >>
> >>Anne Le Mouel
> >>EDF R&D
> >>Centre des Renardières
> >>Dept ADEB
> >>Route de Sens-Ecuelles
> >>77 818 Moret-sur-Loing
> >>FRANCE
> >>tel:    33 1 60 73 79 03
> >>Fax:    33 1 60 73 75 69
> >>e-mail: anne.le-mouel@edf.fr
> >
>