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

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

j.osborne@student.unsw.edu.au

+61400063327