The experimental investigation was carried out to study the effect of heat flux, mass flux and inlet subcooling on the local heat transfer coefficient during subcooled flow boiling of water and saturated flow boiling of perfluorohexane in horizontal microchannel heat sink. Precise milling was used for manufacturing two microchannel plates. One of the plates has twenty-one microchannels with cross section of 335x930 m, the another plate has two microchannels with cross section of 2000x360 m. The distributions of local heat transfer coefficients along the length and width of the microchannel plates were measured using thermocouples installed into holes in the copper block with cartridge heaters. The experiments with dielectric fluid perfluorohexane were performed for mass flux 450 kg/m2s and heat fluxes ranging from 1 to 15 W/cm2. The experiments with water were performed for heat fluxes ranging from 25 to 500 W/cm2 and mass flux ranging from 480 to 4700 kg/m2s. For perfluorohexane, it was obtained that the evaporation of thin liquid film becomes decisive mechanism of heat transfer for heat flux less than 6 W/cm2. For heat flux higher than 12 W/cm2 nucleate boiling suppressing in thin liquid films causes the heat transfer deterioration. The subcooled flow boiling of water in short microchannel shows the obvious impact of mass flux on the value of heat transfer coefficient. Using data for perfluorohexane and water, two existing heat transfer correlations for flow boiling were verified and show good agreement with the experimental data.
|Журнал||International Heat Transfer Conference|
|Состояние||Опубликовано - 1 янв 2018|
|Событие||16th International Heat Transfer Conference, IHTC 2018 - Beijing, Китай|
Продолжительность: 10 авг 2018 → 15 авг 2018