Abstract:
A solar-energy based vapor absorption refrigeration system is
potentially an excellent alternative air-conditioning system.
However, there are several research challenges to ensure
sufficient efficiency and reliability for ensuring widespread
implementation. Integration of a parabolic trough solar collector
utilizing a mixture of nanoparticles and water with a vapor
absorption system has the potential to significantly enhance the
efficiency of the system. Such a system makes use of the
superior thermo-physical properties of the nanofluid compared
to the base fluid. Moreover, the direct absorption phenomenon
of solar radiation through interaction with the participating
medium (nanofluid) results in a higher temperature rise of the
medium in conjunction with higher operating efficiencies as
well. At the same time there are certain challenges that need to
be identified and addressed in the implementation of this novel
concept. For instance, to make it reliable, the system further
needs to be integrated with a thermal storage system which
facilitates air-conditioning even during non-sunshine hours.
Integration of vapor absorption refrigeration technology,
parabolic trough with water-nanoparticles mixture as the
absorbing medium and a thermal storage facility is the
uniqueness of this design which under certain conditions and
locations may prove to be an efficient and reliable substitute to
the conventional electrical air-conditioning systems. In this
particular study a space cooling application for approximately
100 Tons of refrigeration is studied. Hourly variation in sunlight
as well as seasonal changes for temperate climate conditions is
considered. Parameters such as the cooling load of the space,
and waste heat produced by electronics are evaluated. The
cooling system driven by the nanofluid-based concentrated
parabolic solar collector is mathematical modeled and then the
optimization is done by varying the nanoparticle size and
volume fraction in order to obtain the best result for collector
outlet temperature, thermal efficiency and optical efficiency
