TY  - EJOU
AU  - Zhang, Ying 
AU  - Dang, Chao 
AU  - Zhang, Zhiqiang 

TI  - Experimental Study on Flow Boiling Characteristics of Low-GWP Fluid R1234yf in Microchannels Heat Sink
T2  - Frontiers in Heat and Mass Transfer

PY  - 2025
VL  - 23
IS  - 4
SN  - 2151-8629

AB  - In this study, the flow boiling characteristics of R1234yf in parallel microchannels were experimentally investigated. The experiments were conducted with heat flux from 0 to 550 kW/m<sup>2</sup>, mass flux of 434, 727, and 1015 kg/(m<sup>2</sup> s), saturation temperatures of 293, 298, and 303 K, and inlet sub-cooling of 5, 10, and 15 K. The analysis of the experimental results provides the following conclusions: a reduced mass flux and lower subcooling correspond to a diminished degree of superheat at the boiling inception wall; conversely, an elevated saturation temperature results in a reduced amount of superheat at the boiling inception wall. Furthermore, an increase in sub-cooling and saturation temperature will enhance heat transfer efficiency. The wall temperature is mostly influenced by variations in saturation temperature and is minimally related to changes in mass flux and subcooling degree. An increase in mass flux results in a greater pressure drop attributed to heightened frictional pressure loss. The variation in pressure drop with respect to sub-cooling is minimal, while an increased saturation temperature correlates with a reduced pressure drop due to the formation of smaller bubbles and lowered frictional pressure loss at high saturation pressures. This study thoroughly examines and summarizes the effects of mass flow rate, saturation temperature, and subcooling on the flow-boiling heat transfer and pressure drop characteristics of R1234yf. Furthermore, the new correlation has 93.42% of the predicted values fall within a 15% mean absolute error, exhibiting a mean absolute error of 5.75%. It provides a superior method for predicting the flow-boiling heat transfer coefficients of R1234yf in the heat sink of parallel microchannels compared to existing correlations.
KW  - Flow boiling; microchannels; high heat flux; heat transfer; pressure drop

DO  - 10.32604/fhmt.2025.067373