IEA Solar Heating and Cooling Programm - NachhaltigWirtschaften.at

IEA SHC Task 38 Solar Air Conditioning and Refrigeration Subtask C2-A, November 9, 2009
Conclusion
In this report the new development concerning simulation tools for solar cooling are
presented. First are presented the most commonly used simulation tools in the domain of
solar air conditioning. It was shown that most of simulation tools requires high knowledge of
the simulated process as well as internal development for each project, except some simple
simulation tools with predefined configurations and fixed boundaries. Most of simulation
environment used in each research group in the solar cooling domain are internally
developed and used. In the commercially available detailed softwares; the models of the
solar installation are widely used as in found in the libraries, however the model of the
cooling process itself are usually re-developed by the users.
New development of solar cooling models and their validation are then presented. A detailed
desiccant air handling unit powered by heat pipe vacuum tube collectors is developed and
implemented in SPARK. The model of the unit showed good accuracy on a component level
and on a system level under different operating conditions. The supply conditions of the air
handling unit are estimated with good accuracy as well as the potential of solar energy in the
desiccant cooling process. The transient behaviour of the collector is very well predicted by
the model. A transient model of the desiccant wheel is also developed and experimentally
validated. The model calculates the evolution of the temperature and humidity ratio of the air
across the wheel and at its outlet. It gives also a good estimation of the mean air outlet
conditions of the desiccant wheel.
A transient detailed model of a Li/Br absorption chiller is developed. The model is
experimentally validated and is capable to predict the transient behaviour of the chiller. The
comparison with experimental data shows that the dynamic agreement between experiment
and simulation is very good with dynamic temperature deviations between 10 and 25 s The
dynamic simulation model presented is a useful tool in the overall design process of
absorption chillers. Technical changes in the construction of an existing absorption chiller
model can be tested quickly and easily by incorporating the design changes in the model.
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