IEA Solar Heating and Cooling Programm - NachhaltigWirtschaften.at

IEA SHC Task 38 Solar Air Conditioning and Refrigeration Subtask A Report A-D3b, Date: December 2010
System scheme
System performance
The small-scale solar heat driven cooling (SHDC) system has been put into operation in
2005. The monitoring campaign carried out by Austrian Institute of Technology allows the
assessment of the energy system performance from September 2006 till September 2008.
Based on the measurement data following conclusion regarding the energy system
performance can be stated:
- Around 1,026 kWh chilled water has been produced by the SHDC system during the
entire monitoring period. This corresponds to around 70 full load hours. The solar
system including flat-plate collector and hot water storage did provide around
2,356 kWh heat to the adsorption chiller which leads to a seasonal performance
factor of SPF = 0.435. The annual electricity generation efficiency with reflects the
ratio of produced energy of chilled water and the consumed electricity of the overall
SHDC system is calculated to 3.39.
- The SHDC system energy performance can be distinguished between two different
categories:
o High chilling capacity and energy efficient system performance:
The solar thermally driven absorption system operates with coefficient of
performance COP factors corresponding to manufacturer data. Cold water
temperatures are in the range of 12°C and the absorption chiller operates in
the capacity range of 5 to 15 kW cold . In all three hydraulic circuits of the chiller
nominal temperature level are achieved.
o Low chilling capacity and inefficient system performance:
The absorption chiller operates with COPs significantly lower than nominal
COP according to manufacturer data. Especially during the starting phase the
nominal chilling capacity of 15 kWcold is not achieved. The required
temperature levels in all three water circuits around the chiller are insufficient
and the chiller operates mainly under low part load conditions.
- Heat rejection – the applied wet open cooling tower operates efficiently und supplies
sufficient cooling water temperatures to the absorption chiller. Till September 1,700
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