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Title: A correlation for nucleate flow boiling in small channels

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%.
Authors:
 [1] ;  [2] ;  [3] ;  [4]
  1. Texas Tech Univ., Lubbock, TX (United States). Dept. of Mechanical Engineering|[Argonne National Lab., IL (United States)
  2. Argonne National Lab., IL (United States)
  3. Texas Tech Univ., Lubbock, TX (United States). Dept. of Mechanical Engineering
  4. Univ. of Illinois, Chicago, IL (United States). Dept. of Mechanical Engineering
Publication Date:
OSTI Identifier:
508127
Report Number(s):
ANL/ET/CP--92074; CONF-9706130--1
ON: DE97007093; TRN: 97:004692
DOE Contract Number:
W-31109-ENG-38
Resource Type:
Conference
Resource Relation:
Conference: Compact heat exchangers for the process industries conference, Snowbird, UT (United States), 22-27 Jun 1997; Other Information: PBD: 1997
Research Org:
Argonne National Lab., IL (United States)
Sponsoring Org:
USDOE Assistant Secretary for Energy Efficiency and Renewable Energy, Washington, DC (United States)
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING NOT INCLUDED IN OTHER CATEGORIES; PHASE CHANGE MATERIALS; NUCLEATE BOILING; HEAT TRANSFER; HEAT EXCHANGERS; REFRIGERANTS; TUBES