A correlation for nucleate flow boiling in small channels

Conference · Fri Aug 01 04:00:00 EDT 1997

OSTI ID:508127

Tran, T N ^[1]; Wambsganss, M W ^[2]; Chyu, M C ^[1]; France, D M ^[3]

---

1. Texas Tech Univ., Lubbock, TX (United States). Dept. of Mechanical Engineering
2. Argonne National Lab., IL (United States)
3. Univ. of Illinois, Chicago, IL (United States). Dept. of Mechanical Engineering

Compact heat exchangers are becoming more attractive for applications in which energy conservation, space saving, and cost are important considerations. Applications exist in the process industries where phase-change heat transfer realizes more compact designs and improved performance compared to single-phase heat transfer. However, there have been only a few studies in the literature reporting on phase-change heat transfer and two-phase flow in compact heat exchangers, and validated design correlations are lacking. Recent data from experiments on flow boiling of refrigerants in small channels have led researchers to conclude that nucleation is the dominant heat transfer mechanism over a broad range of heat flux and wall superheats. Local heat transfer coefficients and overall two-phase pressure drops were measured for three different refrigerants with circular and non-circular channels in a range of pressures. This data base supports the nucleate boiling mechanism, and it was used to develop a new correlation for heat transfer in nucleate flow boiling. The correlation is based on the Rohsenow boiling model, introducing a confinement number defined by Kew and Cornwell. The new correlation predicts the experimental data for nucleate flow boiling of three refrigerants within {+-}15%.

• Research Organization: Argonne National Lab., IL (United States)
• Sponsoring Organization: USDOE Assistant Secretary for Energy Efficiency and Renewable Energy, Washington, DC (United States)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 508127
• Report Number(s): ANL/ET/CP--92074; CONF-9706130--1; ON: DE97007093
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
HEAT EXCHANGERS
HEAT TRANSFER
NUCLEATE BOILING
PHASE CHANGE MATERIALS
REFRIGERANTS
TUBES