11

Recovery of Heavy Fuel Oil from Sunken Ships

by High Frequency Induction Heating Method

Shoichi Hara, Osamu Miyata, Masao OnoNational Maritime Research InstituteHiroyasu KifuneTokyo University of Science and TechnologySukekazu ShimonishiNippon Salvage Co., Ltd

NATEC 2016

22

Contents of presentation

(1) Introduction

(2) Outline of experiment

(3) Experimental results

(4) Discussions

(5) Numerical calculation

（6） Conclusion

33

Necessity of recovering oil remained in the ship tank

●When the ship sinks loaded with the cargo oil or fuel oil due to marine disaster, the oil recovery is required because of the risk reduction of oil discharge and marine environment protection,

●The operation of the oil recovery from sunken vessels is extremely difficult in winter or in deep water, because the fluidity of oil in the tank is quite low.

44

Principle of technique （High Frequency Induction Heating Method）

alternate current →magnetic flux change→eddy current→Joule heat generation

coil metal

power

power

coil

IH electromagnetic cooker Induction heating principle

55

Heavy fuel oil recovery system

Heating system ①Direct heating unit: heating unit inside the hull

②Side hull heating unit: heating of heavy fuel oil

outside the hull by heat transfer

Assuming the case of impossibility of direct heating inside the hull, the target is to develop the system for providing the heat from outside of the hull. Schematic idea

IH unit

IH unit

suction pipe

high frequency inverter

sunken wreck

IH unit

IH unit

suction pipe

high frequency inverter

sunken wreck

①

②

6

Characteristics of heavy fuel oil recovery system

Advantage

●The induction heating recovery system needs no large-scale facilities such as boilers.

●The power can sufficiently be supplied from auxiliary generator on the salvaging vessel.

7

ρl(kg/m3)

y = -0.0008x + 0.9920.95

0.955

0.96

0.965

0.97

0.975

0.98

0 10 20 30 40 50 60

T(℃）

log（ν）

log(ν） = -0.0327T + 3.9211

0

1

2

3

4

5

0 10 20 30 40 50 60

T(℃）

Outline of experiment

Experimental parameter

●H

●L

●φd

●with/without heat

Physical property of

heavy fuel oil

Logarithmic kinematic viscosity

density

L

h

water

heavy oil

work coil

gravity tank

reservoir tank

Φｄ

heavy oil tank

circulating water channel

water

water

HL

h

water

heavy oil

work coil

gravity tank

reservoir tank

Φｄ

heavy oil tank

circulating water channel

water

water

H

(ｃSt)

schematic idea of the experimental arrangement

tank size:06x0.6x0.6m

88

Outline of experiment

schematic idea of the experimental arrangement

Gravity tank

Reservoir tank

Water

Heavy fuel oil

Work coil

Heavy oil tank

WaterLoad cell

W

Gravity tank

Reservoir tank

Water

Heavy fuel oil

Work coil

Heavy oil tank

WaterLoad cell

W

99

Measurement by thermo coupleｓ

unit:mm

central section

600mm

300 mm

heated area

Oil outletx

yz

Water inlet ：thermo sensor

12345

6

7

89

1011

12

13141516

17

600mm

300 mm

heated area

Oil outletx

yz

Water inlet ：thermo sensor

12345

6

7

89

1011

12

13141516

17

No ｘ ｙ ｚ1 5 5 3002 5 10 3003 5 50 3004 5 100 3005 5 300 3006 5 500 3007 5 595 3008 300 5 3009 300 10 300

10 300 50 30011 300 100 30012 300 300 30013 450 5 30014 450 10 30015 450 50 30016 450 100 30017 450 300 30018 595 5 30019 595 10 30020 595 50 30021 595 100 30022 595 300 30023 595 500 30024 595 595 30025 450 5 526 450 10 527 450 50 528 450 100 529 450 300 5

30-3741-48

horizontal pipeheated pipe

1010

Experimental conditions

Exp.No.P ipe length

L（ｍ ）

PipediameterｄΦ （mm）

Waterpressure

head ｈ（ｍ）

Heat time（min）

Mat size（ｍ）

Watertemperature

(℃ ）

Atmospheretemperature

(℃ ）

O iltemperature

(℃ ）

Electric powerbefore oil

recovery （W）

Heating position during oilrecovery

Electric powerduring oil

recovery （W）

Recoveryrate

(kg/s)

1 4 25 4 － － 28.2 － － － － － 0.0577

2 4 25 4 － － 24.8 － － － － － 0.0539

3 2 25 4 － － 28.0 － － － － － 0.1050

4 2 32 4 － － 28.0 － － － － － 0.2310

5 4 32 4 － － 27.9 － － － － － 0.1710

6 4 32 2 － － 27.7 － － － － － 0.1090

7 2 32 2 － － 27.7 － － － － － 0.1570

8 2 25 2 － － 27.7 － － － － － 0.0699

9 4 25 4 － － 27.4 － － － － － 0.0372

10 4 25 4 120 0.2 25.1 － － 400 Top （Center） 400 0.0767

11 4 25 4 120 0.6 24.5 － － 600 Top （Center） 600 0.0818

12 2 25 4 120 0.6 23.5 － － 600 Top （Center） 600 0.1280

13 4 32 4 240 0.6 23.1 － － 600 Top （Center） 600 0.1740

14 4 25 4 0 － 29.3 30.7 28.6 － － － 0.0771

15 4 25 4 10 0.2 28.8 28.9 28.6 400 Top （Center） 400 0.0813

16 4 25 4 30 0.2 29.1 27.8 28.7 400 Top （Center） 400 0.0803

17 4 25 4 60 0.2 28.1 27.8 28.2 400 Top （Center） 400 0.0808

18 4 25 4 120 0.2 27.3 26.9 27.1 400 Top （Center） 400 0.0705

19 4 25 4 120 0.2 27.1 26.4 26.7 400 Top (Recovery side) 400 0.0693

20 4 25 4 120 0.2 25.0 25.6 26.4 400 Side plate 400 0.0696

21 4 25 4 10 0.2 25.8 26.0 26.1 2000 Top （Center） 2000 0.0671

22 4 25 4 － － 12.3 11.1 12.3 － － － 0.0118

23 4 32 4 － － 11.7 11.0 11.7 － － － 0.0224

24 4 32 2 － － 11.6 11.0 11.6 － － － 0.0119

25 4 25 2 － － 11.6 11.7 11.6 － － － 0.0052

26 4 25 4 － 0.2 11.3 10.3 13.5 － Pipe(Recovery side) 400 0.0144

27 4 25 4 － 0.2 11.1 10.3 13.2 － Pipe(Recovery side) 1000 0.0181

28 4 25 4 － 0.2 11.2 10.1 12.7 － Pipe(Recovery side) 2000 0.0230

29 4 25 4 120 0.2 11.4 9.6 11.5 2000 Top （Center） 2000 0.0085

30 4 25 4 120 0.2 10.9 9.8 12.2 2000 Top＋ Pipe 4000 0.0305

1111

Experimental materials and instrument

oil tank

work coil non-woven fabric

set-up of thermo couple Inverter unit

1212

Work coil of pipe type

41ch

43ch

42ch

45ch

44ch

47ch

46ch

48ch

41ch

43ch

42ch

45ch

44ch

47ch

46ch

48ch

thermocouple

heated pipe

work

coil

un-woven fabric

41ch

43ch

42ch

45ch

44ch

47ch

46ch

48ch

41ch

43ch

42ch

45ch

44ch

47ch

46ch

48ch

thermocouple

heated pipe

work

coil

un-woven fabric

1313

Gravity tank and reservoir tank

oil tank

gravity tank gravity tank

oil tank and pipe reservoir tank

load cell

1414

Estimation of oil recovery rate with various experimental conditions

0

0.05

0.1

0.15

0.2

0.25

0 0.0005 0.001 0.0015

Hd4/Lν

Q(k

g/se

c)

no heating

pipe heating

mat heating

Cal

LHgdQ

o

w

128

4

1515

Estimation of oil recovery rate concerning oil temperature on certain experimental condition

0

0.02

0.04

0.06

0.08

0.1

0.12

0 10 20 30 40

temperature(℃）

Q(k

g/se

c)

no heatingpipe heatingmat heatingCal

1616

L2z1

油

gravity tank

reservoir tank

heavy oil tank

ℓ3

P1 V1

P2 V2

Hζ1

ζ2

λ１

ζ4

ζ3

λ2z2

ℓ1

ℓ2

L2z1

油

gravity tank

reservoir tank

heavy oil tank

ℓ3

P1 V1

P2 V2

Hζ1

ζ2

λ１

ζ4

ζ3

λ2z2

ℓ1

ℓ2

Friction loss factor

2L

22

22221

21

22o

2

22

22

4

22

3

23

1

11

23

2

23

12

2222

111

Vd

VV

VdLVVVgzPVgzP

oo

wwwooww

Bernoulli's principle

friction loss coefficient of elbow.

321 ,,

4

friction loss coefficient of entrance

INLETOUTLET

20

1717

Relation between Reynolds number

and friction loss factor

1

10

100

1000

10000

0.01 0.1 1 10

Re

λ

no heatingpipe heatingmat heatingCal 2

2VdL

gHo

w

VdRe

6464

laminar flow

Exp.

1818

Relation between loaded electric

power and improved ratio by heating

1.0

1.2

1.4

1.6

1.8

2.0

2.2

2.4

2.6

2.8

0 1000 2000 3000 4000 5000

power(W)

impr

ove

d r

atio

mat heatingpipe heating

pipe＋mat

10 min.pre-heating

mat size0.6m

10min. ～ 2 hourspre-heating

19

Numerical simulation

CFD tool : FLUENT

mesh for half model

　density 977.2 (kg/m3)　specific heat 2093.025 （kcal/kg℃）

　thermal conduction rate 0.1453 （kcal/mh℃）

　viscous coefficient 1.9544 （kg/ms）　cubical expansion coefficient 0.00099 （/K）　density 7850 (kg/m3)　specific heat 498.13 （kcal/kg℃）　thermal conduction rate 52.3256 （kcal/mh℃）

oil

iron

physical properties of oil and iron

19

20x=5 300 450 595

595

500

300

100

50

10

y=5

T=7200sec（Exp_9)

39.5-40.5

38.5-39.5

37.5-38.5

36.5-37.5

35.5-36.5

34.5-35.5

33.5-34.5

32.5-33.5

31.5-32.5

30.5-31.5

29.5-30.5

28.5-29.5

27.5-28.5

26.5-27.5

25.5-26.5

24.5-25.5

23.5-24.5

22.5-23.5

Particle trajectory and temperature distribution

heating

mmExperimental resultsNumerical results

Exp.9

525sec

1000sec

1680sec

20

21

x=5 300 450 595y=595

500

300

100

50

10

5

T=0（Exp_9)

25-25.5

24.5-25

24-24.5

23.5-24

23-23.5

22.5-23

22-22.5

x=5 300 450 595y=595

500

300

100

50

10

5

T=60secc（Exp_9)

24.5-25

24-24.5

23.5-24

23-23.5

22.5-23

x=5 300 450 595y=595

500

300

100

50

10

5

T=300sec（Exp_9)

28.5-29.5

27.5-28.5

26.5-27.5

25.5-26.5

24.5-25.5

23.5-24.5

22.5-23.5

x=5 300 450 595y=595

500

300

100

50

10

5

T=600sec（Exp_9)

32.5-35

30-32.5

27.5-30

25-27.5

22.5-25

x=5 300 450 595y=595

500

300

100

50

10

5

T=1200sec（Exp_9)

37.5-40

35-37.5

32.5-35

30-32.5

27.5-30

25-27.5

22.5-25

x=5 300 450 595y=595

500

300

100

50

10

5

T=1800sec（Exp_9)

40-42.5

37.5-40

35-37.5

32.5-35

30-32.5

27.5-30

25-27.5

22.5-25

x=5 300 450 595y=595

500

300

100

50

10

5

T=0（Exp_9)

25-25.5

24.5-25

24-24.5

23.5-24

23-23.5

22.5-23

22-22.5

x=5 300 450 595y=595

500

300

100

50

10

5

T=60secc（Exp_9)

24.5-25

24-24.5

23.5-24

23-23.5

22.5-23

x=5 300 450 595y=595

500

300

100

50

10

5

T=300sec（Exp_9)

28.5-29.5

27.5-28.5

26.5-27.5

25.5-26.5

24.5-25.5

23.5-24.5

22.5-23.5

x=5 300 450 595y=595

500

300

100

50

10

5

T=600sec（Exp_9)

32.5-35

30-32.5

27.5-30

25-27.5

22.5-25

x=5 300 450 595y=595

500

300

100

50

10

5

T=1200sec（Exp_9)

37.5-40

35-37.5

32.5-35

30-32.5

27.5-30

25-27.5

22.5-25

x=5 300 450 595y=595

500

300

100

50

10

5

T=1800sec（Exp_9)

40-42.5

37.5-40

35-37.5

32.5-35

30-32.5

27.5-30

25-27.5

22.5-25

Change of temperature distribution

600sec 1200sec 1800sec

300sec0sec 60sec

50mm10mm

Exp.9

21

22

Change of temperature distribution

x=5 300 450 595595

500

300

100

50

10

y=5

T=2400sec（Exp_10)

47.5-50

45-47.5

42.5-45

40-42.5

37.5-40

35-37.5

32.5-35

30-32.5

27.5-30

25-27.5

22.5-25

x=5 300 450 595595

500

300

100

50

10

y=5

T=3000sec（Exp_10)

47.5-50

45-47.5

42.5-45

40-42.5

37.5-40

35-37.5

32.5-35

30-32.5

27.5-30

25-27.5

22.5-25

x=5 300 450 595595

500

300

100

50

10

y=5

T=4200sec（Exp_10)

47.5-50

45-47.5

42.5-45

40-42.5

37.5-40

35-37.5

32.5-35

30-32.5

27.5-30

25-27.5

22.5-25

x=5 300 450 595595

500

300

100

50

10

y=5

T=4800sec（Exp_10)

47.5-50

45-47.5

42.5-45

40-42.5

37.5-40

35-37.5

32.5-35

30-32.5

27.5-30

25-27.5

22.5-25

x=5 300 450 595595

500

300

100

50

10

y=5

T=5400sec（Exp_10)

47.5-50

45-47.5

42.5-45

40-42.5

37.5-40

35-37.5

32.5-35

30-32.5

27.5-30

25-27.5

22.5-25

x=5 150 300 450 595595

500

300

100

50

10

y=5

T=6000sec(Exp10)

47.5-50

45-47.5

42.5-45

40-42.5

37.5-40

35-37.5

32.5-35

30-32.5

27.5-30

25-27.5

22.5-25

50mm10mm

2400sec 3000sec 4200sec

4800sec 5400sec 6000sec

Exp.9

22

2323

small coil（100×100mm） large coil（150×150mm）

Coil arrangement on top plate

Reservoir tank

Water

Heavy oil

Work coilh

L

H d

Heavy oil tank

WaterLoad measure

WGravity tank

Arrangement of work coil In another experiment

Oil recovery system

2424

Measuring positions of thermo couples

仕切り板

蓋

油出口

タンク壁面の穴位置

５

150

５

150

510

50

100

５300

117 177

7５

正面図 平面図

①

②

③④

⑤

⑥ ⑦

⑧

⑨

⑩

⑪

⑧ ⑪

⑮

⑯

⑰

⑱⑲

⑳

㉑㉒

㉓

㉘

⑰ ㉓

㉗

㉙

㉚

㉛ ㉜

㉔㉕

㉖

⑫⑬

⑭

仕切り板

蓋

油出口

タンク壁面の穴位置

５

150

５

150

510

50

100

５300

117 177

7５

正面図 平面図

①

②

③④

⑤

⑥ ⑦

⑧

⑨

⑩

⑪

⑧ ⑪

⑮

⑯

⑰

⑱⑲

⑳

㉑㉒

㉓

㉘

⑰ ㉓

㉗

㉙

㉚

㉛ ㉜

㉔㉕

㉖

⑫⑬

⑭

Position of the hole of the tank

Top view

Partition plate

Tank ｌid

Oil outlet

Front view

2525

Exp.No.

Pipelength

L（ｍ）

Pipediameterｄd

（mm）

Water pressurehead ｈ（ｍ）

Heat timebefore Exp.

（min）

Mat size &number of

use（ｍ） ×

Watertemperature

(℃）

Atmospheretemperature

(℃）

Oiltemperature

(℃）Heating position

Injectionelectricity

（W）

Recoveryrate

(kg/min)

1 4 25 4 － － 13.3 12.4 15.3 － － 0.72

2 4 25 4 － 　0.2×２ 12.9 12.1 13.9 Central edge 2000 0.90

3 4 25 4 120 　0.2×1 11.0 10.2 11.6 Ｃenter rear 2000 0.58

4 4 25 4 － 　0.14×２ 9.9 9.6 11.7 Central edge 2000 0.37

5 4 25 4 － 　0.2×２ 9.9 10.5 9.2 Ｏne side edge 2000 0.52

6 4 25 4 － 　0.14×２ 9.8 9.0 11.5 Central edge 2000 0.49

Experimental conditions and results

2626

Time history of oil recovery weight in each case of experiments

2727

y = 8E+06x-2.05

y = 3839.8x-1

0.0

0.5

1.0

1.5

2.0

2.5

1500 2000 2500 3000 3500 4000 4500 5000

Q(k

g/m

in.)

ν（ｃSt)

Exp_1

Exp_2

Exp_3

Exp_4

Exp_5

Exp_6

mean line

Cal.

without heating

Relation between oil recovery rate and kinematic viscosity of oil

2828

Modeling for computer simulation

2929

Streamline of oil and water inside the model tank (Section distance：X=0.3m，t=50sec)

Streamline of oil and water inside the model tank (Section distance：X=0.15m，t=100sec)

Streamline of oil and water inside the model tank (Section distance：X=0.3m，t=100sec)

Streamline of oil and water inside the tank

3030

Streamline of oil and water inside the model tank (Section distance：X=0.3m，t=50sec)

Streamline of oil and water inside the model tank(Section distance:X=0.15m，t=100sec)

Streamline of oil and water inside the model tank (Section distance：X=0.3m，t=100sec)

1680 sec

1000 sec

Without partitionWith partition

Comparison of streamline of oil and water inside the tank

Experimental conditions and oil recovery rate

Pipe length ： 4 mPipe diameter ： 25 mmWater pressure head ： 4 mWater temperature ： 25.1 ℃Electric power before oil recovery ： 400 w/2 hour

3131

(1) The oil recovery rate has been estimated by the simple method using various parameters.

(2) The improved oil recovery rate comparing with the case of no heating as for the pipe type of heating increases linearly with the increase of electric power.

(3) The combination of pipe and mat type of heating can improve the oil recovery rate.

Conclusion

3232

(4) The numerical calculation results of oil temperature inside the tank does not agree well with the experimental results and represent the natural convection of heat

(5) The heating at the cutout part of the partition plate does not improve the effect of fluidization.

(6) The size of the coil mat does not show the significant difference of the oil recovery efficiency.

(7) The partition plate prevents the oil from fluidizing because of making the route of water. This phenomenon is seen in the practical operation of salvage.

Conclusion

3333

Thank you for your kind attention.