Paper presented at the 8th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Mauritius, 11-13 July, 2011.
Desiccant-based Air Handling Units (AHU) can guarantee
significant technical and energy/environmental advantages
related to the use of traditional ones (with dehumidification by
cooling). For these reasons, a test facility has been located in
Benevento (Southern Italy), in which a silica-gel desiccant
wheel is inserted in an AHU which treats outside air only. For
this wheel, the regeneration temperature can be as low as 65 °C,
therefore energy savings and emissions reductions are more
consistent when the regeneration of the desiccant material is
obtained by means of available low grade thermal energy, such
as that from solar collectors or cogenerators.
In the actual configuration, regeneration is obtained by
means of thermal energy recovered from a micro-cogenerator
(MCHP, Micro Combined Heat and Power) based on a natural
gas-fired reciprocating internal combustion engine, eventually
integrated through a natural gas-fired boiler.
Future activity aims to reduce the regeneration fossil
energy requirements by introducing a solar collector system
that substitutes or integrates thermal energy supplied by the
To this aim, a commercial software has been used to design
the solar collector system (collectors type, absorber area, water
flow rate…) considering the thermal power and temperature
requirements of the regeneration process.
The existing AHU and the designed solar collector system
have been successively simulated by means of TRNSYS
software, in order to evaluate operational data and performance
parameters of the system in a typical week of operation, e.g.
thermal-hygrometric conditions of air in the mean sections of
the AHU, solar collectors efficiency and solar fraction.