An experimental and numerical study of plug formation in vertical pipes during cryogenic pipe freezing
An experimental and numerical study of plug formation in vertical pipes during cryogenic pipe freezing
Pipe freezing, the method and its application are reviewed together with previous research into this and closely related problems. In particular the research carried out by the Southampton University Pipe Freezing Group is summarised.
The Construction of an experimental rig is described together with details of its instrumentation to measure the temperature profiles and heat flow during pipe freezing.
The experimental results are analysed and a hypothesis to rationalise the observations is put forward. This is that, when pipe freezing water in vertical pipes, plug formation occurs in three phases. During Phase One the boundary layer due to natural convection exists from above the freezing zone to below it. Phase two is commenced when the growing plug has reduced the orifice sufficiently to allow the water returning up the centre of the pipe to mix with the water in natural convection boundary layer. The water in the centre moving upwards is turned near the centre section of the plug to flow downwards over the lower part of the plug. Natural convection in the upper part of the freezing zone is very significantly reduced to leave a "sump" of cooled water in this volume which freezes more rapidly than the remainder of the plug. Phase three of plug formation covers the axial extension of the plug after initial freeze-off.
The various mathematical modelling techniques for use with moving boundary problems, such as pipe freezing, are reviewed. The development of a one-dimensional finite difference computer model, specific to the pipe freezing problem, is described and results from it are compared to those obtained experimentally.
University of Southampton
Burton, Mark John
96c07471-e763-4863-81f9-f2267f1f850c
1986
Burton, Mark John
96c07471-e763-4863-81f9-f2267f1f850c
Wigley, D. A.
478aad3b-8b4d-4cde-8c53-cb35b0992a60
Burton, Mark John
(1986)
An experimental and numerical study of plug formation in vertical pipes during cryogenic pipe freezing.
University of Southampton, Doctoral Thesis, 264pp.
Record type:
Thesis
(Doctoral)
Abstract
Pipe freezing, the method and its application are reviewed together with previous research into this and closely related problems. In particular the research carried out by the Southampton University Pipe Freezing Group is summarised.
The Construction of an experimental rig is described together with details of its instrumentation to measure the temperature profiles and heat flow during pipe freezing.
The experimental results are analysed and a hypothesis to rationalise the observations is put forward. This is that, when pipe freezing water in vertical pipes, plug formation occurs in three phases. During Phase One the boundary layer due to natural convection exists from above the freezing zone to below it. Phase two is commenced when the growing plug has reduced the orifice sufficiently to allow the water returning up the centre of the pipe to mix with the water in natural convection boundary layer. The water in the centre moving upwards is turned near the centre section of the plug to flow downwards over the lower part of the plug. Natural convection in the upper part of the freezing zone is very significantly reduced to leave a "sump" of cooled water in this volume which freezes more rapidly than the remainder of the plug. Phase three of plug formation covers the axial extension of the plug after initial freeze-off.
The various mathematical modelling techniques for use with moving boundary problems, such as pipe freezing, are reviewed. The development of a one-dimensional finite difference computer model, specific to the pipe freezing problem, is described and results from it are compared to those obtained experimentally.
Text
86074591
- Version of Record
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Published date: 1986
Identifiers
Local EPrints ID: 460752
URI: http://eprints.soton.ac.uk/id/eprint/460752
PURE UUID: d2addef3-dd5a-4683-bdbc-9b29abe3a1e1
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Date deposited: 04 Jul 2022 18:29
Last modified: 16 Mar 2024 18:42
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Contributors
Author:
Mark John Burton
Thesis advisor:
D. A. Wigley
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