Thermoelectric cooling of electronic devices with nanofluid in a multiport minichannel heat exchanger

• 9.15% decrement in ΔT is observed for nanofluid with 0.2 vol.% of Al2O3.
• For the same ΔT the nanofluids give enhanced thermoelectric cooling capacity.
• Local Nu significantly increased at the entrance region due to particle migration.
• Minichannel effectiveness increased with increase in nanoparticles concentration.

The performance of thermoelectric cooling of electronic devices with nanofluid in a multiport minichannel heat exchanger is experimentally investigated. The Bismuth Telluride (BiTe3) thermoelectric cooler (TEC) with a ΔTmax of 67 °C is used to extract heat from the electronic devices, which is a power transistor. The power transistor in the circuit board usually operates with the electric power ranging from 20 W to 400 W which is considered as the input power to the TEC. The aluminum oxide (Al2O3)–water nanofluid with volume concentrations of 0.1% and 0.2% is used as the coolant to remove the heat from the hot side of the TEC. The Reynolds number is varied from 200 to 1000. The result showed 40% enhancement in the coefficient of performance (COP) of thermoelectric module for 0.2% of nanoparticle volume concentration. A 9.15% decrement in thermoelectric temperature difference between the hot and cold side has also been observed for nanofluids (0.2 vol.%), which enhanced the module cooling capacity. The enhancement in local Nusselt number is found to be 23.92% for 0.2% of nanoparticles volume concentration when compared with that of water at a Reynolds number of 1000 and at 400 W power input. The migration of nanoparticles due to temperature difference (thermophoresis) from the wall of the minichannel to the center is attributed to be the reason for the higher local Nusselt number at the entrance region. The thermal effectiveness of the cooling system increases with increase in volume concentration which makes the nanofluids as a promising coolant for electronic cooling applications.