A study of boiling water flow regimes at low pressures

"A comprehensive experimental program to examine flow regimes at pressures below 100 psia for boiling of water in tubes was carried out. An electrical probe, which measures the resistance of the fluid between the centerline of the flow and the tube wall, was used to identify the various flow re...

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Main Authors: Fiori, Mario P., Bergles A. E.
Other Authors: Massachusetts Institute of Technology. Dept. of Mechanical Engineering.
Format: Technical Report
Published: Cambridge, Mass. : M.I.T. Dept. of Mechanical Engineering, [1966] 2011
Subjects:
Online Access:http://hdl.handle.net/1721.1/61448
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author Fiori, Mario P.
Bergles A. E.
author2 Massachusetts Institute of Technology. Dept. of Mechanical Engineering.
author_facet Massachusetts Institute of Technology. Dept. of Mechanical Engineering.
Fiori, Mario P.
Bergles A. E.
author_sort Fiori, Mario P.
collection MIT
description "A comprehensive experimental program to examine flow regimes at pressures below 100 psia for boiling of water in tubes was carried out. An electrical probe, which measures the resistance of the fluid between the centerline of the flow and the tube wall, was used to identify the various flow regimes. This probe proved to be an ideal detection device, because of its simplicity, reproducibility, and accurate representation of the flow pattern within the heated test section. The major flow regimes observed were bubbly, slug and annular flow. Under certain conditions at high flow rates, a wispy-annular flow patern was observed. The effects of mass velocity (0.2 x 10 - 2.4 x 100 lbm/hr-ft2), inlet temperature (100, 150, 2000F), exit pressure (30, 100 psia), quality (x = -10 - +7 percent), purity (9, 40 PPM NaCl; 1-3 megohm-cm), length (L/D-30, 6Q, 90), diameter 0.094, 0.242 in.), and orientation (vertical and horizontal on the flow regimes were studied. Flow regime maps on coordinates of mass velocity and quality are presented for these conditions. Bubbly and slug flow occurred primarily in the subcooled region, while fully developed annular flow was reached at equilibrium qualities between 2 and 4 percent. The transitions between the different flows were shifted to regions of increased subcooling when velocity, pressure, and heat flux increased, and when inlet temperature decreased. Purity and geometry had little affect on the flow regime boundaries.
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spelling mit-1721.1/614482019-04-10T18:05:58Z A study of boiling water flow regimes at low pressures Fiori, Mario P. Bergles A. E. Massachusetts Institute of Technology. Dept. of Mechanical Engineering. Massachusetts Institute of Technology. National Magnet Laboratory. Massachusetts Institute of Technology. Heat Transfer Laboratory. Boiling-points. Pipe -- Fluid dynamics. Heat -- Transmission. "A comprehensive experimental program to examine flow regimes at pressures below 100 psia for boiling of water in tubes was carried out. An electrical probe, which measures the resistance of the fluid between the centerline of the flow and the tube wall, was used to identify the various flow regimes. This probe proved to be an ideal detection device, because of its simplicity, reproducibility, and accurate representation of the flow pattern within the heated test section. The major flow regimes observed were bubbly, slug and annular flow. Under certain conditions at high flow rates, a wispy-annular flow patern was observed. The effects of mass velocity (0.2 x 10 - 2.4 x 100 lbm/hr-ft2), inlet temperature (100, 150, 2000F), exit pressure (30, 100 psia), quality (x = -10 - +7 percent), purity (9, 40 PPM NaCl; 1-3 megohm-cm), length (L/D-30, 6Q, 90), diameter 0.094, 0.242 in.), and orientation (vertical and horizontal on the flow regimes were studied. Flow regime maps on coordinates of mass velocity and quality are presented for these conditions. Bubbly and slug flow occurred primarily in the subcooled region, while fully developed annular flow was reached at equilibrium qualities between 2 and 4 percent. The transitions between the different flows were shifted to regions of increased subcooling when velocity, pressure, and heat flux increased, and when inlet temperature decreased. Purity and geometry had little affect on the flow regime boundaries. (cont.) The shifting of the transitions is related to the agglomeration point, which is that point at which the bubbles so coalesce that slug flow is first observed. The agglomeration point depends on the point of incipient boiling, the number of bubbles in the flow, and the number of collisions per bubble. These latter quantities in turn depend on velocity, temperature, pressure, and heat flux. The flow regime information obtained in this study s~hould be of value in correlating and interpreting low pressure heattransfer data. The flow regime data were found to be useful in explaining the effect of inlet temperature on burnout heat flux. Sponsored by the Solid State Sciences Division, Air Force Office of Scientific Research D.S.R. 2011-03-04T23:27:33Z 2011-03-04T23:27:33Z 1966 Technical Report 14072571 http://hdl.handle.net/1721.1/61448 Technical report (Massachusetts Institute of Technology, Heat Transfer Laboratory) ; no. 40. ix, 81 p application/pdf Cambridge, Mass. : M.I.T. Dept. of Mechanical Engineering, [1966]
spellingShingle Boiling-points.
Pipe -- Fluid dynamics.
Heat -- Transmission.
Fiori, Mario P.
Bergles A. E.
A study of boiling water flow regimes at low pressures
title A study of boiling water flow regimes at low pressures
title_full A study of boiling water flow regimes at low pressures
title_fullStr A study of boiling water flow regimes at low pressures
title_full_unstemmed A study of boiling water flow regimes at low pressures
title_short A study of boiling water flow regimes at low pressures
title_sort study of boiling water flow regimes at low pressures
topic Boiling-points.
Pipe -- Fluid dynamics.
Heat -- Transmission.
url http://hdl.handle.net/1721.1/61448
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