Re: [TRNSYS-users] Immersed heat exchangers

["Jeff Thornton" <thornton@tess-inc.com>]

> While TYPE534 (TESS) is very robust and fast, it asks for many physical
> and geometric parameters that are not usually available in the catalogs
> and that, anyway, I can not ask to the user. My first question is: does
> somebody know a set of "typical" values for these parameters?, i.e.,
> values that apply for most of the small tanks (lets say <500 liters) in
> the market.

What we typically do in cases like this is to find several immersed coil
heat exchanger tanks on the internet from a manufacturer, and then
pre-define several tanks for the user to choose from in TRNSED.  Then
behind the scenes you can set all of the parameters that the user doesn't
want to enter like coil pitch, tube diameter, etc.  All of this
information is available from many manufacturer's.

The user then sees:

Storage Tank Type

and has options for:

1) Typical 200 Liter tank
2) Typical 500 Liter tank
3) Premier 200 Liter tank

etc.

I'm not fond of the constant UA tank approach and find it does not capture
the dynamics associated with varying inlet conditions typical of natural
convection heat exchangers in solar storage tanks.

Jeff

Jeff Thornton
President - TESS, LLC

2916 Marketplace Drive - Suite 104
Madison WI 53719 USA

Phone: 608-274-2577
Fax: 608-278-1475
E-mail: thornton@tess-inc.com
Web: www.tess-inc.com