Question about type 1 (Solar Collector)

["Jong, M.J.M." <jong@xxxxxx>]

Dear TRNSYS users,

Now I am busy with a simulation of a system with a solar collector, a heat
exchanger an a storage tank for a hot water system for a house. For the heat
exchanger I use the integrated heat exchanger in type 1 (Solar Collector).
The tenth parameter of type 1 indicates the effeciency of the heat
exchanger.

The necessary inputs are among other things the solar radiation, the flows
through the collector and the heat exchanger and the inlet temperature of
the fluid of the cold side of the heat exchanger. The outputs of type 1 are
the the outlet temperature of the flow of the cold side of the heat
exchanger, the flow trough the collector, the rate of energy gain and the
outlettemperature of the flow through the collector.

I think that the inlet temperature of the flow trough the collector depends
on the efficiency of the heat exchanger. The worse the efficiency of the
heat exchanger, the less the temperarure difference between the inlet and
outlet of the flow through the heat exchanger. I remarked that you cannot
find this effect in TRNSYS. Type 1 (Solar Collector) supposes that the inlet
temperature of the flow through the cold side of the heat exchanger and the
inlet temperature of the flow through the collector are equal. I think this
is not correct. Does anybody has an idea to avoid this problem ?

I also remarked another strange thing in type 1 (Solar Collector). When I
use the quadratic efficiency mode (parameter 1 is 1) and the first order
coefficient of the efficiency curve is 0, then the collector outlet
temperature and the outlet temperature of the cold side of the heat
exchanger are equal. This is independent of the efficiency of the heat
exchanger. I think this is not possible. Does anybody has an explanation
herefor ?  

With kind regards,


Maurice Jong 

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Maurice Jong
ECN - Energy Research Foundation      Department: Zon, Group DEGO
P.O. box 1    1755 ZG  Petten              Country:   The Netherlands
Telephone:    (+31) 224 564938             Fax:       (+31) 224 568966
E-mail: jong@ecn.nl                             Internet:
http://home.soneraplaza.nl/mw/prive/mjmjong/

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