# Cfd Filling

Topics: Liquefied natural gas, Natural gas, Density Pages: 9 (567 words) Published: March 31, 2013
CFD SIMULATION OF LIQUEFIED NATURAL GAS( LNG )
BEHAVIOR DURING TANK FILLING
Student Name
FU FANG XIONG (B040910067)
Course
BMCT
Contact Number:
014-9312439
Supervisor
MOHD SHUKRI ZAKARIA

OBJECTIVE
1. To evaluate rapid pressure rise inside the storage tank.
2. To study and simulate behavior of Liquefied Natural Gas during tank filling by CFD.

SCOPE
1. Study of the phenomenon when mixing two different density of LNG inside a tank. 2. Simulation of LNG behavior during tank filling in term of density by using CFD. 3. Evaluation of the effect of feed rate, initial height of heel LNG, and density condition on stratification. Validation :

Fluent Numerical Models :

Fakulti Kejuruteraan Mekanikal
Universiti Teknikal Malaysia Melaka
Kampus Industri
75450 Melaka, MALAYSIA

Boil-Off-Gas

Student’s Email :
oryonfoo@yahoo.com
Heel LNG
Inlet (Feed)
t=0

Multiphase (3 Phases)
Mixture Model
Free Surface Flow
Buoyant Flow

t=25s

t=50s

Graph 1: Validation Result

Figure 1: Simulation Model

Well agreement between present
study simulation with experiment
( Koyama,2008)
Relative Percentage Error: 8.76%

Result:

Different Feed Rate

t=300s

0
0

5

10

15

20
0.02m/s

-0.5

0.04m/s
0.06m/s

-1

0.08m/s
-1.5

Density Difference
ρmixture – ρheel / ρheel )*100

Density Different
(ρmixture – ρheel / ρheel )*100

t=100s

Different Initial Height of Heel
0
-0.5

10

15
1m

-1.5

1.5

-2

2m

-2.5

3m

-3

Graph 2: Different Feed Rate

H/D*100

Graph 3: Different Initial Height Of Heel

Relative Density Difference
((ρfeed,initial – ρheel / ρheel )*100)

t=1300s

5

-1

h/D*100

t=1000s

0

Comparison Between Each Criterion
0
0

5

10

15

20

Feed Rate (0.02m/s)

t=1600s

t=1800s

Figure 2 : Density Contour (30 min)

0
-0.05

0

5

10

15

20

-0.1
-0.15

2

-0.2

4

-0.25

6

-0.3

8

-0.35

Density Difference
ρmixture – ρheel / ρheel )*100

Density Different
(ρmixture – ρheel / ρheel )*100

-0.2

Feed Rate (0.04m/s)

-0.4

Feed Rate (0.06m/s)
Feed Rate (0.08m/s)

-0.6

Initial Height(1m)
initial height(1.5m)

-0.8

Initial Height(2m)

-1

Initial Height(3m)

-1.2

Rel. Density Dif.(2)
Rel. Density Dif.(4)

-1.4

Rel. Density Dif.(6)

-0.4

h/D*100
Graph 4: Relative Density Difference

-1.6

h/D*100

Rel. Density Dif.(8)

Graph 5: Comparison Between Each Criterion

Discussion:

REFERENCES

Graph 2– Lower Feed Rate Contributed to less density difference and less stratification.( Increase Time Contact) Graph 3– Deeper Height of Heel LNG Contributed to less density difference and less stratification. (Increase Surface Contact area.

Graph 4– Lower Relative Density Difference Contributed to less density difference and less stratification Graph 5– In General, Relative Density Difference( Green line) is MOST significant to stratification if compared to the other criterions.

1. Koyama, K. (2008). CFD Simulation on
LNG Storage Tank to Improve Safety, Ef- 
ficiency and Reduce Cost. International 
Gas Union Research Conference Paris
Conclusion and Recommendation:
2008 , 11.

Student’s Signature:

Objective Achieved
Low feed rate, deep height of heel LNG, and low relative density difference are suggested to reduce stratification and rollover affect as well.
The most perfect and only way to counter stratification problem is to prevent mixing 2 different density LND into one tank ( no relative density difference).

Gantt Chart( PSM II ):
Supervisor’s Signature:
I’m HERE!

Stamp: