IEA Solar Heating and Cooling Programm - NachhaltigWirtschaften.at

IEA SHC Task 38
Monitoring Procedure
Q2 _ total sum = Q2S
_ fossil + Q2D
_
= Q2 _
fossil + Q2 _ RES = Q2S
+ Q2D
fossil + Q2S
_ RES + Q2D
_ RES
Eq. 29
One special application of the Eq. 28 is when the heat from the back up source is only
directly used, i.e.
[ ]
Q 2S _ fossil + Q2S _ RES = Q2S = 0 kWh th
Eq. 30
Under Eq. 30, Eq. 28 becomes:
SF Q1s
= hotstorage Q1 +
Eq. 31
Q2D
The losses through the buffer tank are calculated as the difference between the input and
the output, if the latter is known.
Q _ loss _ stge
= (Q1 + Q2S _ fossil + Q2S_ RES) − (Q1S)
[ ] kWh th
Eq. 32
In case, the output of the storage tanks is not known and the buffer tank is shared with the
heat back-up system, the efficiency of the storage can be estimated as follows:
Q _ loss _ stge = (Q1 + Q2S _ fossil + Q2S_ RES) − (Q3a + Q4 + Q3b + Q6)
[ ] kWh th
Eq.
33
In the considered case, Q_loss_stge coincides with the overall losses in the system, which
are given by:
19 99% draft Version