Nanofluids for heat exchange applications
Miniaturization of electronic components has led to the demand for development of new compact heat exchangers and also cooling fluids with higher heat transfer performance. Conventional cooling liquid can be modified by adding solid particles with higher thermophysical properties. Nanofluids are colloidal dilute dispersion of nanoparticles (generally less than 5% in volume) such as metals, oxides, carbides, or carbon nanotubes in conventional coolants or base fluids such as water, ethylene glycol, and oil. In this research project thermal conductivity and viscosity of nanofluids are measured and the performance is compared with that of the base fluids. Furthermore, nanofluids are tested in three different convective experimental setups to evaluate the behaviour and the performance. The first test setup includes: a 1.5 m long, 3.7 mm diameter straight stainless steel tube which is used to investigate the behaviour of nanofluids in laminar and turbulent flow regimes. The second test section consists of a cold plate, minichannel heat exchanger, connected in parallel to the first test rig. The third test section, a 30 cm long, 0.5 mm diameter straight stainless tube is used to study the nanofluids’ performance under laminar flow conditions. This project is a part of the EU project NanoHex (Enhanced Nano-fluid Heat Exchange) funded by the Seventh Framework Programme.