TY - JOUR
T1 - Boiling of R290+CF3i mixture inside an offset strip fin plate heat exchanger
AU - Prabakaran, Rajendran
AU - Salman, Mohammad
AU - Kumar, Poongavanam Ganesh
AU - Lee, Dongchan
AU - Kim, Sung Chul
N1 - Publisher Copyright:
© 2022 Elsevier Ltd
PY - 2022/11/5
Y1 - 2022/11/5
N2 - In this study, evaporation characteristics of mildly flammable R290 + CF3i mixture (35 % + 65 % by weight) were conducted experimentally in an offset strip fins (OSSF) embedded plate heat exchanger (PHEX). Various operating conditions, namely, saturation temperature (Tsat), heat flux (q), inlet vapor quality (xin), and mass flux (G), were considered in the range of 5–15 °C, 4–10 kW m−2, 0.1–0.8, and 40–80 kg m−2 s−1, respectively. From this study, it was found that nucleate boiling was quenched at lower xin regardless of the operating conditions, although the boiling process was led by convection at high xin. Except at higher G, there was a presence of dry-out at a mean x ranging between 0.36 and 0.50, while the two-phase frictional pressure drop increased steadily with mean x. The heat transfer coefficient was largely augmented with increments in G of 50.15 %, followed by increments in q and T of 15.1 % and 12.3 %, respectively. Similarly, the two-phase frictional pressure drop was increased by 12.3 % and 175.4 % with increases in q and G, respectively, although it diminished by 21.9 % with Tsat. Compared to R1234yf, the mean HTC of R290 + CF3i was 6 % lower with 7 % increased TP-FPD. Additionally, Nusselt number and friction factor correlations have been developed with excellent predictability of 7 % and 12 % of mean absolute error, respectively.
AB - In this study, evaporation characteristics of mildly flammable R290 + CF3i mixture (35 % + 65 % by weight) were conducted experimentally in an offset strip fins (OSSF) embedded plate heat exchanger (PHEX). Various operating conditions, namely, saturation temperature (Tsat), heat flux (q), inlet vapor quality (xin), and mass flux (G), were considered in the range of 5–15 °C, 4–10 kW m−2, 0.1–0.8, and 40–80 kg m−2 s−1, respectively. From this study, it was found that nucleate boiling was quenched at lower xin regardless of the operating conditions, although the boiling process was led by convection at high xin. Except at higher G, there was a presence of dry-out at a mean x ranging between 0.36 and 0.50, while the two-phase frictional pressure drop increased steadily with mean x. The heat transfer coefficient was largely augmented with increments in G of 50.15 %, followed by increments in q and T of 15.1 % and 12.3 %, respectively. Similarly, the two-phase frictional pressure drop was increased by 12.3 % and 175.4 % with increases in q and G, respectively, although it diminished by 21.9 % with Tsat. Compared to R1234yf, the mean HTC of R290 + CF3i was 6 % lower with 7 % increased TP-FPD. Additionally, Nusselt number and friction factor correlations have been developed with excellent predictability of 7 % and 12 % of mean absolute error, respectively.
KW - Evaporation
KW - Frictional pressure drop
KW - Heat transfer coefficient
KW - Plate heat exchanger
KW - Refrigerant mixture
UR - http://www.scopus.com/inward/record.url?scp=85135501557&partnerID=8YFLogxK
U2 - 10.1016/j.applthermaleng.2022.119070
DO - 10.1016/j.applthermaleng.2022.119070
M3 - Article
AN - SCOPUS:85135501557
SN - 1359-4311
VL - 216
JO - Applied Thermal Engineering
JF - Applied Thermal Engineering
M1 - 119070
ER -