Flow boiling heat transfer characteristics of R123 and R134a in a micro-channel

A general criterion for evaporative heat transfer in micro/mini-channels

“…6 shows a comparison between the newly proposed correlation and the overall database. As calculated in Table 2 [19], with high Bond numbers like 23.2, but also predicts In and Jeong's datasets [23] with low Bond numbers, such as 0.037. The mean absolute error and standard deviation are both in acceptable ranges.…”

“…Table 1 lists the experimental data of two-phase heat transfer in micro/mini-channels, which covers the fluids of R12, R134a, R11, R123, water, CO 2 , R410a, R22, ethanol, R236fa, R245fa, and propane at various heat fluxes, mass fluxes, and qualities. There are two types of micro/mini-channel geometries: one is circular channels in highly conductive metal (copper, aluminum, stainless steel, or brass) [5][6][7][9][10][11][12][13][14][17][18][19][22][23][24][25], the other is rectangular channels in silicon or metal substrate [5,[7][8][15][16][20][21]. The latter can be 3-side or 4-side heated.…”

“…The latter can be 3-side or 4-side heated. Tests were conducted with single-channel [5][6][7][9][10][11][13][14][17][18][19][20][22][23][24][25] and multi-channel [8,12,[15][16]21] configurations.…”

High-speed shadow imaging in internal flow pattern and macroscopic characteristics of a R134a flash-boiling spray discharged through a vertical twin-orifice atomizer

“…Martín-Callizo et al (2007) experimentally investigated subcooled flow boiling heat transfer for R134a in vertical cylindrical tubes, and they found higher system pressure and smaller channel diameter lead to better boiling heat transfer. Flow boiling heat transfer in a single circular micro-channel has been experimentally investigated with R134a for various experimental conditions by In and Jeong (2009), they stated that nucleate boiling of R134a was dominant heat transfer mechanism until its suppression at high vapor quality and then two-phase forced convection heat transfer became dominant. Selvaraju and Mani (2006) experimentally investigated the performance of a vapour ejector refrigeration system using R134a as working fluid.…”

Analysis of Evaporative Heat Transfer by Expansion Bubble in a Microchannel for High Heat Flux Cooling

“…Hence, in this study, high heat flux cooling by evaporative heat transfer of the liquid film in a microchannel is proposed. In and Jeong (19) pointed out that, even in a microchannel, nucleate boiling was generated in a liquid film depending on the refrigerant properties. Therefore, maintaining low wall superheat is required to avoid nucleate boiling, and a much smaller microchannel should be required to generate a thinner liquid film.…”