[TRNSYS-users] energy unbalanced, solar absorption cooling system (UNSW)

[Jeremy Osborne]

Hi,

 

I am modelling a solar thermal double effect absorption chiller system with
conventional backup. 

 

I cannot get the energy of the Tank TYPE534, collector TYPE536, and double
effect chiller TYPE677 to balance, and likely to be significantly affecting
the results. 46% error (relative to Useful Gain). 

 

This is one energy balance used. 

Q(useful gain) +Q(chilled water) + Q(electricity) - Q(tank losses) -
Q(Cooling Water) = 0 (but doesn't)

 

When I run the system on steady state 800W/m2 then the error is 7% (relative
to useful gain of collector) when pure water is used in the heat exchanger
in the tank. If I manually enter the values for the fluid in the heat
exchanger in the tank , still to be pure water then the error is 0.11%. 

However, under transient radiation values the tank does not converge, and
still produces 46% error when forced. 

 

I think the problem lies in the tank. Both the chiller and collectors have
been validated against manufactures values. 

Can you please assist in resolving the problem?

 

Attached should be zip folder of project with necessary files.

 

Kind regards,

 

Jeremy Osborne 

 

UNSW engineering - undergrad thesis student

 <mailto:j.osborne at student.unsw.edu.au> j.osborne at student.unsw.edu.au

+61400063327

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/trnsys-users-onebuilding.org/attachments/20090917/e1dbbc38/attachment-0001.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: TRNSYS.zip
Type: application/x-zip-compressed
Size: 443738 bytes
Desc: not available
URL: <http://lists.onebuilding.org/pipermail/trnsys-users-onebuilding.org/attachments/20090917/e1dbbc38/attachment-0001.bin>