TY - GEN
T1 - Flow patterns and pressure drop of vertical upward flows in a tube with header-like protrusions with R134a
AU - Qian, Hongliang
AU - Hrnjak, Pega
N1 - Publisher Copyright:
© 2019 International Institute of Refrigeration. All rights reserved.
PY - 2019
Y1 - 2019
N2 - Flow patterns and pressure drop in a vertical tube with header-like protrusions in adiabatic conditions are presented. Three major flow patterns are observed with a high-speed camera in the mass flow rate range studied in this paper: slug flow, churn flow and annular flow. The flow pattern map is proposed. As the distance between two measurement ports along the tube decreases, pressure drop of refrigerant flows in the tube with protrusions decreases for all vapor qualities and mass flow rates. The relation is close to linear. However, the relation between pressure drop between two certain ports and quality is not linear. For relatively larger mass flow rate, as the quality increases from 0, pressure drop decreases first and then increases. There is a smallest pressure drop at moderate quality. The smallest pressure drop among all the qualities between two certain ports happens decrease from x=1 to x=0.6 as mass flow rate increase from 3 g/s to 7.5 g/s. If the quality is kept to be constant, DP is smaller for higher mass flow rate for relatively small qualities. However, in the high-quality range, DP is larger for higher mass flow rate.
AB - Flow patterns and pressure drop in a vertical tube with header-like protrusions in adiabatic conditions are presented. Three major flow patterns are observed with a high-speed camera in the mass flow rate range studied in this paper: slug flow, churn flow and annular flow. The flow pattern map is proposed. As the distance between two measurement ports along the tube decreases, pressure drop of refrigerant flows in the tube with protrusions decreases for all vapor qualities and mass flow rates. The relation is close to linear. However, the relation between pressure drop between two certain ports and quality is not linear. For relatively larger mass flow rate, as the quality increases from 0, pressure drop decreases first and then increases. There is a smallest pressure drop at moderate quality. The smallest pressure drop among all the qualities between two certain ports happens decrease from x=1 to x=0.6 as mass flow rate increase from 3 g/s to 7.5 g/s. If the quality is kept to be constant, DP is smaller for higher mass flow rate for relatively small qualities. However, in the high-quality range, DP is larger for higher mass flow rate.
KW - Pressure drop
KW - R134a
KW - Refrigerant
KW - Vertical flow
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U2 - 10.18462/iir.icr.2019.0844
DO - 10.18462/iir.icr.2019.0844
M3 - Conference contribution
AN - SCOPUS:85082723511
T3 - Refrigeration Science and Technology
SP - 1223
EP - 1230
BT - ICR 2019 - 25th IIR International Congress of Refrigeration
A2 - Minea, Vasile
PB - International Institute of Refrigeration
T2 - 25th IIR International Congress of Refrigeration, ICR 2019
Y2 - 24 August 2019 through 30 August 2019
ER -