Performance improvement of absorption chillers: A review on nanoparticle addition
M. Venegas, M. de Vega, N. García-Hernando
Abstract
A review on the use of nanoparticles to improve the performance of absorption chillers is presented. The review includes a compilation and discussion of research data on the subject using as base fluids NH 3 -H 2 O, H 2 O-LiBr and other solutions. Topics analysed include: theoretical and experimental studies about mass transfer enhancement in absorbers and desorbers; research to improve performance of complete absorption chillers; evaluation of thermophysical properties and stability of nanofluids, including viscosity, surface tension, thermal conductivity and other properties; and other studies with results useful for implementation in absorption chillers. Trends about the use of nanofluids in absorption systems, type and concentration of nanoparticles that provide the best performances and specific topics that require more research are identified from the review. Strategies are proposed for future research or for decision makers related to absorption chillers. • Research data about nanofluids including NH 3 -H 2 O and H 2 O-LiBr are presented. • Theory and experiments on devices, stability and properties are reviewed. • Trends about the use of nanofluids in absorption systems are summarized. • Type and fraction of nanoparticles that provide the best performances are found. • Specific topics that require more research are identified.