Environmental Engineering Reference
In-Depth Information
Hot
Hot
Auxiliary
heater
Auxiliary
heater
Storage 2
Storage 2
Storage 1
Storage 1
Cold
Cold
Figure 3.17
Collector Systems with Two Storage Tanks
increase the solar fraction significantly. If the first storage tank is fully loaded,
the control switches to the second storage tank. An auxiliary heater can heat
up the second storage tank in both systems. Figure 3.17 shows the two
described concepts with two storage tanks.
Swimming pools
The pool itself is the heat storage medium of a swimming pool system. The
usefulness of the system lies in the storage. The solar heating system must
compensate only for the storage losses, i.e. the losses of the pool (Figure 3.18).
The pool losses
Q
•
Pool,loss
consist of convection losses
Q
•
conv
, radiation losses
Q
•
rad
, vaporization losses
Q
•
vap
and transmission losses
Q
•
trans
:
(3.46)
The transmission losses
Q
•
trans
from the swimming pool to the earth can be
neglected for solar-heated outdoor pools during the summer season.
Vaporization
losses
Radiation and
convection losses
Solar radiation
gains
•
Q
vap
•
•
•
Q
RC
= Q
rad
+
Q
conv
•
•
Q
sol
•
Q
aux
•
Q
trans
Auxiliary
heating
Transmission
losses to
the earth
Figure 3.18
Energy Balance of a Swimming Pool
