ISSN Online: 2379-1748
ISBN Flash Drive: 978-1-56700-469-4
ISBN Online: 978-1-56700-470-0
Second Thermal and Fluids Engineering Conference
ENHANCING THE HEAT TRANSFER CHARACTERISTICS OF LIQUID DESICCANTS WITH NANOPARTICLES
In order to enhance the heat transfer characteristics of liquid desiccants utilized in dehumidification process, addition of nanoparticles (<100 nm) is proposed. To study the heat transfer characteristics of the liquid desiccant with nanoparticles the crucial thermo-physical property required is the thermal conductivity. The impact on thermal conductivity and its variation due to the presence of dispersed nanoparticles is investigated in this study. Another important thermo-physical property is the viscosity which determines the pumping power required for circulation of the liquid desiccant. Four models for thermal conductivity and three models for viscosity have been selected for this study. Several parameters such as temperature and concentration of the desiccant and the volume fraction of nanoparticles are considered for three liquid desiccants, namely, lithium bromide, calcium chloride and lithium chloride. Three types of nanoparticles are considered: aluminum oxide, copper, and titanium oxide. All models predict that increasing the volume fraction of nanoparticles caused a significant increase in thermal conductivity of the liquid desiccant. The increase in thermal conductivity is due to the increase in temperature of the liquid desiccant. Increase in the concentration resulted in a decrease in the thermal conductivity. As the volume fraction of nanoparticles was increased the viscosity of the liquid desiccant also increased. The results showed that the highest values of viscosity were obtained for lithium chloride and the highest values of thermal conductivity were obtained for calcium chloride with copper nanoparticles whereas the lowest values of both viscosity and thermal conductivity were obtained for lithium bromide.