Heat Transfer, Basic Relations

1
Heat Transfer, Basic Relations
Conduction
Free convection Forced convection
Overall
Radiation
2
Heat Transfer, Basic Relations Convection -
Finding h

• General
• a-e empirical constants
• Hand calculations
• using charts
• Computer simulations
• Forced convection in pipes
• Re gt 10,000
• 0.7 lt Pr lt 700
• L/D gt 60
• Error gt 30, large effect on axial T gradient

3
An Analytical SS Flowing Bundle Model For Up To 3
Internal Lines T.J. Danielson et al., Conoco
(1999), SPE 56719 Heat balance for the inner
(i) pipelines Heat balance for the carrier
(c) pipe Nu determined in OLGA using
Dittus-Boelter Solving linear, coupeled ODEs
for all pipes
4
Agbami Manifold Transient Thermal Analysis A.B.
Sandøy, ABB, 2000
PIPE DIAMETRE
10 8
6 INSULATION DATA (Tymar 10K)

Insulation Thickness, mm, assuming gas
content 40 46 53 Insulation Thickness, mm,
assuming oil content 20 25 31 INSULATION
DATA (Vicotherm)
Insulation Thickness,
mm, assuming gas content 41 46 51 Insulation
Thickness, mm, assuming oil content 24 29 35 Neop
rene between Pipe and Vicotherm, mm 3 3
3 Neoprene between Vicotherm and sea, mm 3
3 3 Total (gas/oil)

47/30 52/35 57/41