RE: Pressure drop in water pipes

[Michaël Kummert <kummert@xxxxxxxxxxxxx>]

Dear Apple Chan,

I would suggest to compute the pumping energy required vs. the flowrate outside TRNSYS, using your detailed pressure drop for the whole circuit. You can then also take into account the electrical efficiency of the motor and derive new power coefficients that take both effects into account. (I hope this makes sense...)

There are no known issues related to moving deck files and/or projects from one computer to another, assuming that they are not using path names that do not exist on one of the machines. Both Trnsys installations also have to include all non-standard components, of course. Lastly, it is known that some email programs corrupt IISiBat .tpf files if you do not zip them before attaching them to an email (but I assume you were not emailing the files).

Here is a longer reply about that problem from Dave Bradley:

There is no fundamental problem with moving .dck or .tpf files from one PC to
another. They should still run provided that all the paths are the same from
one computer to the other - in other words if TRNSYS is installed on the c:\
drive of one machine and the d:\ drive of another, you may have problems.

One trick that will help is to make sure that you path names are enclosed in
quote marks - this is necessary if you have any spaces in the path and may also
help if you do not.

If you are using TRNSHELL to write your input file, you can use the following
syntax when assigning list and output files in order to make things a little
easier:

ASSIGN "***.lst"   6
ASSIGN "***.out"  10
ASSIGN "***.ou1"  11
etc.

The *** indicates to TRNSYS that it should append the deck name (including its
entire path) onto the specified file extension. In this manner you can more
easily change the name of the .dck and still have it run.

Lastly, if you are getting a TRNSYS based error, the list file should give you
some information about the nature of the problem. If you are getting a "project
load failed" error from IISiBat, then you may have a corrupted project. In
either case, you can always contact your distributor for help with specific
problems.


Regards,

Michaël Kummert



_________________________________________________

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@engr.wisc.edu

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




> -----Original Message-----
> From: owner-trnsys@relay.doit.wisc.edu
> [mailto:owner-trnsys@relay.doit.wisc.edu] On Behalf Of Apple Chan
> Sent: Thursday, February 27, 2003 03:18
> To: trnsys@relay.doit.wisc.edu
> Subject: Pressure drop in water pipes
>
>
> Dear all
>
> 1. It is found that the pressure drop due to friction inside
> water pipe has not been considered in the Type 31 pipe
> component in TRNSYS.  How can we include this effect since
> the magnitude of pressure drop inside water pipe will
> influence the energy consumption of water pump?
>
> 2. Even the first question is solved, how the pressure drop
> can be related to the energy consumption of the water pump
> since the energy consumption of the water pump is related to
> flow rate and the power coefficients only?
>
> 3. It always happen that when a TRNSYS input file (*.TPF or
> *.dck) is transferred from one PC to another, the simulation
> cannot be run.  Is there anyone who has this kind of
> experience before?
>
> Many thanks,
>
> Apple Chan
> 27 Feb. 2003
>