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Re: Internal header pressure drop calculation (TYPE 45)

on 2004-02-18 13:09, jsalazar@xxxxxxxxxxxxxxxx wrote:

Dear TRNSYS users,

TYPE 45 calculates the pressure drop in the collector headers internally if
experimental data is not available. The procedure is explained on page 4.2.2-5
of the TRNSYS manual.  I managed to derive the term S1 assuming equal mass flow
in each header (I found S1*A11 to be the pressure drop in the lower header).
What I don’t seem to grasp is the S2 term and the equation 4.2.2.9, which
differs from what is in the TYPE 45 source code. This formula (in the manual,
not in the source code) obviously presents a problem since the added terms in it
have different units. I would like to know if there is any available reference
(book, article, whatever) that explains this calculation procedure a little more
explicitly.

In addition to the references listed in the manual, you can take a look at the following thesis (if you didn't :
Malkin, M. P., (M.S., 1985), "Design Of Thermosyphon Solar Domestic Hot Water Systems."
It is available at:
http://sel.me.wisc.edu/publications/theses/theses2.html

I would hope some TRNSYS users have more recent references, though.

I am also confused by Equation 4.2.2.9 and the code. Please keep me informed if you solve the mystery.

Michaël

--
_________________________________________________________

Michaël Kummert

Solar Energy Laboratory - University of Wisconsin-Madison
1303 Engr Res Bldg, 1500 Engineering Drive
Madison, WI 53706

Tel: +1 (608) 263-1589
Fax: +1 (608) 262-8464
E-mail: kummert@xxxxxxxxxxxxx

SEL Web Site: http://sel.me.wisc.edu
TRNSYS Web Site: http://sel.me.wisc.edu/trnsys