Attachment 1-heat Transfer Calculation Sheet

DAI HUNG GAS PIPELINE HEAT TRANSFER CALCULATION SHEET Description: Heat Transfer Calculation

Doc. Title:

Pipeline Cathodic Protection Design

Case:

16-inch Dai Hung Gas Pipeline

Doc. No.:

DHG-PVE-DD-2-CR-REP-102

Appendix: Prepared: Checked:

-

Rev. Date: Date:

Purpose: The evaluation of anode surface temperature installed in 16" gas pipeline. Anodes are installed on 3LPE anti-corrosion coating. I. Pipeline parameters: Inside diameter:

ID

374.6

mm

Outside diameter:

OD

406.4

mm

Wall thickness:

WT

15.9

mm

II. Input data: Thermal conductivity: Thickness, δ

Thermal conductivity, λ

mm

W/m.K

Carbon steel

15.9

54

FBE

0.25

0.38

PE

3.3

0.2

EM

0.2

0.32

Aluminium

40

204

Item

Thermal coefficient: Heat convection coefficient of gas (α1)

100

W/m2.K

Heat convection coefficient of seawater (α2)

600

W/m2.K

45

0

C

28

0

C

Temperature: Maximum operating temperature of pipeline (T1) Maximum seawater temperature at seabed (T2) III. Calculation: t4

Heat transfer coefficient equation:

t5 t6

t3

t7

t2

t1

Gas

Seawater

Heat transfer coefficient: K=

33.40003958

W/m2.K

567.8006729

W/m

39.32

0

Heat Transfer: q=

2

CS

Temperature at surface layers: t2 =

C Page 1

FBE

PE

EM

Al

t8

DAI HUNG GAS PIPELINE HEAT TRANSFER CALCULATION SHEET Description: Heat Transfer Calculation

Doc. Title:

Pipeline Cathodic Protection Design

Case:

16-inch Dai Hung Gas Pipeline

Doc. No.:

DHG-PVE-DD-2-CR-REP-102

Appendix: Prepared: Checked:

-

Rev. Date: Date:

t3 = t4 = t5 = t6 = t7 =

39.15

0

C

38.78

0

C

29.41

0

C

29.06

0

C

28.95

0

C

29.06

0

IV. Result: Temperature at surface anode: T = t6

Notes:

C

CS: Carbon Steel FBE: Fusion Bonded Epoxy PE: Polyethylene EM: Epoxy Mastic (Coating for internal surface of anode)

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