The air collector parameters for solar air collectors are explained in this section.
The collector geometry and specific heat capacity are retrieved from the collector database.
Um den solaren Luftkollektor zu definieren, befolgen Sie diese Schritte:
Go to the System Definition > Solar Loop with Air Collectors variant menu. The definition dialog is opened. You will see the Parameters page. Manufacturer data, geometry, and specific heat capacity are applied from the database and cannot be changed here.
Enter the maximum and minimum volume flow rate.
Every air collector is porous; leakage must be less than 15%.
Enter the correction parameters $\eta_0$, k1 and k2 for calculating the efficiency $\eta$. Using these, the efficiency $\eta$ is calculated using the following formula:
$$ \eta = \eta_0 - \frac{k_1\left(\Delta T \right) + k_2\left(\Delta T \right)^2}{G"} $$
with:
$ G" = irradiation $
$ \Delta T = T_{Air collector,out} - T_{Environment} $
The correction parameters $\eta_0$, k1 and k2 can be found in the testing institute’s records for this collector. However, they are only valid for the tested volume flow rate. In order to be able to simulate with other volume flow rates, you can adjust these correction parameters here. Air collectors usually show lower levels of efficiency with lower volume flow rates.
The efficiency $\eta$ at minimum volume flow is multiplied by the correction factor at minimum flow rate following correction with the above formula. The correction factor is between 0 and 2.
Notes: