Together with the developing nano technology, nano-fluids and nano-particles
are used as working fluid in energy applications. It is foreseen that
nanoparticles have high heat conduction coefficient and it will increase
system performance by using as a working fluid in energy systems. Many
studies in the literature show that nano fluids increase the heat transfer
rate by improving heat transfer. In this study, a performance analysis of an
absorption cooling system using solar energy was performed as numerically.
LiBr-Al2O3/water nano-fluid has been used in the cooling system as working
fluid. The thermodynamic values and calculations used in the analyses were
performed with Engineering Equation Solver program. Heat load necessary for
the generator is provided with a flat plate solar collector. For different
operation condition, the variation of COP values was determined depend on
Al2O3/water nanoparticle concentration ratio. When the Al2O3/water
nanoparticle concentrations are changed as 0%, 0.5% and 0.1%, it was
determined that the COP values increased. Nanoparticles added to the
refrigerant at certain concentration values affects the COP values positively
of cooling systems. Maximum COP value is 0.86 for 85?C generator temperature
and 0.1% Al2O3/water nanoparticle concentration. The lowest COP value was
obtained for the 75 oC generator temperature. When the Al2O3/water
nanoparticle concentration was increased together with the generator
temperature, COP values also increased. When the nanoparticle concentration
of the working fluid increases, the viscosity of the nanofluid can be
increases. Due to, increased viscosity increases the pressure drop in the
flow channel and the pump power required for the flow. Thus, 'minimum
viscosity with maximum thermal conductivity' optimisation in applications is
very important.
Performance Evaluation of the Single-Stage Absorption Cooling System through Energy and Exergy Analysis
