High quality flow boiling heat transfer and pressure drop in microgap pin fin arrays

We investigated two phase heat transfer in staggered and inline micro pin fin arrays, using deionized water and HFE-7200 as working fluids with exit qualities up to 90%. The inline and staggered arrays were wire EDM fabricated to have equivalent pin fin width of 153 μm and height of 305 μm on a heated base area of 0.96 cm width by 2.88 cm length. Mass fluxes ranged from 200 to 600 kg/m2 s for HFE-7200 and 400 to 1300 kg/m2 s for water. Base heat fluxes ranged from 27 to 118 W/cm2 for water, and 1 to 36 W/cm2 for HFE-7200. Average heat transfer coefficient and pressure drop data were obtained and successfully correlated to 3% MAE for water heat transfer coefficient, 10-13% MAE for HFE-7200 heat transfer coefficient, and 15-30% MAE for pressure drop in these pin fin arrays.