IEA Solar Heating and Cooling Programm - NachhaltigWirtschaften.at

IEA SHC Task 38 Solar Air Conditioning and Refrigeration
Subtask A Report, Date:…
Starting from the nominal cooling capacity of the SorTech chiller, the maximum daily cooling
energy can be determined. A 7.5 kW chiller can yield a maximum of 180 kWh of cooling
energy per day, assuming incessant operation. The number of operation hours in a solar
cooling system, however, can be limited by the heat source. An six-hour long operation
would ideally still yield 45 kWh of cooling energy. Figure 5 shows daily cooling energies
between 0 and 23 kWh.
The values vary according to the control strategy, which indirectly reacts to the outside
temperature and solar radiation. In addition, the consumer behaviour must be taken into
account. Constant low values of the cooling capacity imply that the chiller is over-sized for
the system.
Apart from the energy output of the system, it is also very important to look at temperature
levels going in and out the adsorption chiller, as the hot side and the re-cooling temperature
levels can drastically influence the performance. Figure 6 shows the inlet and outlet
temperatures on all three temperature levels at the chiller for a typical August day. The
monitored outside temperature and solar irradiation can be found in the lower graph. The
outside temperature peaked at 32°C and the solar ir radiation reached 917 W/m2. Overall, it
was a bright sunny day with a cloudy passage in the afternoon.