IEA Solar Heating and Cooling Programm - NachhaltigWirtschaften.at

IEA SHC Task 38 Solar Air Conditioning and Refrigeration
Subtask A Report, Date:…
3 Experience report summer 2009
The monitoring of the first cooling season showed that the adsorption chiller worked reliable
and the desired air-conditioning of the office rooms was given. The room temperature in the
offices was kept under 24°C over the whole summer. There weren`t any error operations in
the overall system or in the individual components. The average cooling capacity of the
system lay between 1,7 kW and 2,4 kW, which is way below the nominal capacity of 7,5 kW
of the adsorption chiller. This part load operation caused by the low cooling capacity on the
building side has a negative impact on the thermal Coefficient of Performance (COP th ) as
well as on the electrical Coefficient of Performance (COP el ) of the solar adsorption chiller
system. The documentation of the control was incomplete, which made the check of the
implemented control strategies in the plant through monitoring evaluation quite difficult.
In July 2009, the cold water pump showed a varying electricity consumption. The comparison
between the electricity consumption of the pump and the mass flow in the cold water circle
showed that there was an electricity consumption of the pump, even when the mass flow was
zero. This led to the conclusion that air was in the cold water pipes. Therefore, the water
pipes were de-aired which affected the desired continuous mass flow.
The energy performance of the system is evaluated by two indicators. The Thermal
Coefficient of Performance (COP th ) gives the ratio between produced cooling energy and
used thermal driving energy for a certain period of time (see Equation 1).
Thermal Coefficient of Performance:
COP
Gains Qcooling[
kWh]
Thermal _ Demand Q
_
[ kWh]
= Equation 1
th
=
solar
thermal
The Electrical Coefficient of Performance gives the ratio between the produced cooling
energy and the used electrical consumption for a certain period of time (see Equation 2).
Electrical Coefficient of Performance:
COP
Gains Qcooling[
kWh]
Electricity _ Demand E
,
[ kWh]
= Equation 2
el
=
drivingel