Conductive and Convective Heat Transfer in Inductive Heating of Subsea Buried Pipelines
Publication: Journal of Pipeline Systems Engineering and Practice
Volume 13, Issue 4
Abstract
Inductive heating with high-voltage cables reduces the risk of hydrate formation by raising the temperature of the production fluid in pipelines. Heating the pipeline results in losing a certain fraction of the heat to the surrounding soil through conduction- or convection-dominated flow through the soil. However, the amount of heat lost in conduction versus convection and the transition from conduction- to convection-dominated heat loss remains unknown. Soil permeability, temperature gradient between cable and mudline, and burial depth all influence the mode of heat transfer and the amount of heat lost. We studied the dominant mode of heat transfer in pipelines with inductive heating using 2D finite difference analysis under different soil and environmental conditions. Low permeability soils primarily exhibit conductive heat transfer, thus losing minimum heat to the surrounding soil. In contrast, in highly permeable soils convective flow drives a significant fraction of the heat away from the pipeline and towards the ground surface, barely heating the fluid in the pipe. We identified a critical Rayleigh-Darcy number (1) as the controlling value separating conduction- and convection-dominated heat transfer. An increase in burial depth reduces the heating efficiency in convection-dominated high permeability soils, while it has no effect in conduction-dominated low permeability soils.
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Data Availability Statement
Some or all of the data, models, or code that support the findings of this study are available from the corresponding author upon reasonable request.
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© 2022 American Society of Civil Engineers.
History
Received: Dec 22, 2021
Accepted: Apr 22, 2022
Published online: Jun 28, 2022
Published in print: Nov 1, 2022
Discussion open until: Nov 28, 2022
ASCE Technical Topics:
- Buried pipes
- Cables
- Engineering fundamentals
- Engineering mechanics
- Equipment and machinery
- Flow (fluid dynamics)
- Fluid dynamics
- Fluid mechanics
- Geomechanics
- Geotechnical engineering
- Heat flow
- Heat transfer
- Hydrologic engineering
- Infrastructure
- Measurement (by type)
- Offshore pipelines
- Permeability (soil)
- Pipeline systems
- Pipelines
- Pipes
- Soil dynamics
- Soil mechanics
- Soil properties
- Soil-pipe interaction
- Temperature effects
- Temperature measurement
- Thermodynamics
- Water and water resources
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Cited by
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