Load characteristics of steel and concrete tubular members under jet fire: An experimental and numerical study

Ocean Engineering 37 (2010) 1159–1168

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Load characteristics of steel and concrete tubular members under jet fire: An experimental and numerical study Bong Ju Kim, Jung Kwan Seo, Jeong Hyo Park, Jae Sung Jeong, Byung Keun Oh, Sung Hoon Kim, Chang Hee Park, Jeom Kee Paik n LRET Research Centre of Excellence, Pusan National University, Busan, Republic of Korea

a r t i c l e in fo

abstract

Article history: Received 23 March 2010 Accepted 16 May 2010 Available online 4 July 2010

The aim of this study was to evaluate the load characteristics of steel and concrete tubular members under jet fire, with the motivation to investigate the jet fire load characteristics in FPSO topsides. This paper is part of Phase II of the joint industry project on explosion and fire engineering of FPSOs (EFEF JIP) (Paik and Czujko, 2009; Paik, 2010). To obtain reliable load values, jet fire tests were carried out in parallel with a numerical study. Computational fluid dynamics (CFD) simulation was used to set up an adiabatic wall boundary condition for the jet fire to model the heat transfer mechanism. A concrete tubular member was tested under the assumption that there is no conduction effect from jet fire. A steel tubular member was tested and considered to transfer heat through conduction, convection, and radiation. The temperature distribution, or heat load, was analyzed at specific locations on each type of member. ANSYS CFX, (2008) and KFX, 2007 codes were used to obtain similar fire action in the numerical and experimental methods. The results of this study will provide a useful database to determine design values related to jet fire. & 2010 Elsevier Ltd. All rights reserved.

Keywords: Jet fire load Risk assessment Computational fluid dynamics Fire engineering Floating, Production, Storage and Offloading (FPSO) unit

1. Introduction The Piper Alpha accident of 1988 was the world’s worst offshore oil disaster in terms of both lives lost and impact on the industry (Cullen, 1990). The total insured loss was about £1.7 billion (US$ 3.4 billion), and 167 people were killed. Other major fire accidents caused by gas leaks include the two incidents that occurred on the Enchova Central offshore oil platform in Brazil in 1984 and 1988, the first of which killed 42 people (Alvaro et al., 2001). The possibility of fire hazard has grown as the number of offshore structures has increased. Accurate safety design values are thus required for guidelines on the design of passive fire protection (PFP) and firewalls. Fire action cannot be represented by an analytical expression that can be handled easily. To overcome this problem, an approach based on the numerical calculation for fire loads is needed along with the development of a suitable computing system. Further, there is a lack of standardized methods and coordination for the calculation of fire loads acting on structures and equipment and their corresponding consequences. To provide robust guidance on the design of steel structures to resist jet fires, the characteristics of both fire action and its effects must be

n

Corresponding author. Tel.: + 82 51 510 2429. E-mail address: [email protected] (J. Kee Paik).

0029-8018/$ - see front matter & 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.oceaneng.2010.05.006

identified (Czujko, 2001; Czujko, 2005; Czujko, 2007; Paik and Thayamballi, 2003; Paik and Thayamballi, 2007; Paik, 2010). This paper focuses on the load characteristics of steel and concrete tubular members under jet fire. Generally, fire involves the combination of a combustible vapor or gas with an oxidizer in a combustion process that is manifested by the evolution of light, heat, and flame (Nolan, 1996). Fig. 1 shows the shape of a jet fire with a specific leak direction. Jet fires can arise following the pressurized release of various fuel types (FABIG 2009). The simplest case is a pressurized gas giving rise to a gas jet fire. A pressurized liquid/gas mixture (such as ‘‘live crude’’ or gas dissolved in a liquid) gives rise to a twophase jet fire. The gas content and mechanical energy in the stream atomize the liquid into droplets, which are then evaporated by radiation from the flame. However, the pressurized release of a liquid causes rapid vaporization. This is most likely to occur when a liquid undergoes some degree of superheating, i.e., when it is released from containment at a temperature above its boiling point in ambient conditions, whereupon flash evaporation occurs and a flashing liquid jet fire results. This event may arise from the release of propane or butane. Non-volatile liquids (for example, kerosene, diesel, or stabilized crude) are unlikely to be able to sustain a two-phase jet fire, unless permanently piloted by an adjacent fire, but even so some liquid drop-out is likely, leading to the formation of a pool. In the present study, steel tubular members are used in place of real tubular members of offshore installations to evaluate the

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Nomenclature ds dc Ls Lc ts

external diameter of the steel tubular member external diameter of the concrete tubular member length of the steel tubular member length of the concrete tubular member thickness of the steel tubular member

tc T Pw

r V m R

thickness of the concrete tubular member temperature of the fuel working pressure in the mass flow controller density of the fuel volume rate molecular weight of CH4 gas constant

Fig. 2. Photo of (a) steel and (b) concrete tubular members.

Fig. 1. Photo of a jet fire.

jet fire load, including the effects of conduction, convection, and radiation. However, it is assumed that there is no conduction effect on concrete tubular members, as computational fluid dynamics (CFD) codes set up an adiabatic wall boundary condition. The main objectives of the study were as follows:

 To obtain the ideal jet fire load through numerical and



experimental methods, taking into consideration heat transfer such as conduction, convection, and radiation on steel and concrete tubular members. To study a CFD technique with ANSYS CFX, (2008) and KFX, 2007 for modeling FPSO and offshore structures under jet fire action.

2. Experimental study An analysis of heat load under jet fire is needed to take into account the complicated issues of heat transfer conduction, convection, and radiation. The original objective of this research was to conduct jet fire tests with steel tubular members to which passive fire protection (PFP) had been applied on an offshore plant. However, concrete tubular members were chosen as the PFP material due to the process required to apply PFP, such as

cleaning, blasting, priming, and the addition of mesh work and a top coat. With the steel tubular members, conduction, convection, and radiation effect were considered, whereas with the concrete members it was assumed that heat transfer occurs without conduction. The characteristics of the heat load taking into consideration the effects of convection and radiation were determined. The load characteristics were obtained through jet fire tests for ships and offshore structures conducted at the structural mechanics laboratory of the Pusan National University.

2.1. Parameters for the jet fire tests Before conducting the jet fire tests, it was necessary to classify and analyze the test parameters, including the material type, fuel composition, release rate, data acquisition, flame, and win effect.

2.1.1. Type and size of tubular member Both steel and concrete tubular members were used in the jet fire tests. The steel tubular member was a finished seamless carbon steel pipe, ASTM A106-06 A, ds ¼323.8, Ls ¼1500, and ts ¼8.38 mm, which are similar dimensions to those of pipings in FPSO topsides. The concrete tubular member was a hume pipe, KS F 4403, dc ¼300, Lc ¼2500, and tc ¼30 mm. Fig. 2 shows the two types of members. It is considered that the fire loads may be influenced by the size of tubes, but the present study chose one specific size of the tube noted above because it focuses on the feasibility of applying CFD simulations by comparison with experimental results. Further studies to investigate the effect of tube size are then planned in this regard. The fire testing on different types of tubes such as composite tubes will also be an interesting subject in the future.

B.J. Kim et al. / Ocean Engineering 37 (2010) 1159–1168

2.1.2. Fuel composition Offshore plant and FPSO topsides have various functions, such as oil refining and storage, each of which has its own equipment and area. State-of-the-art liquefied natural gas (LNG) and liquefied petroleum gas (LPG) are particularly in demand among ship owners. Commercial LNG composites are 99% CH4. Thus, methane gas (99.9%) was used in the tests to release the fuel. Table 1 shows the composition of an LNG and LPG.

2.1.3. Release rate It was necessary to calculate the release rate to determine which level of jet fire to use. This is best achieved with an ideal flow function that considers the volume at working pressure which is 4 bar in the present study. Fig. 3 shows the equipment used to control the volume flow. Vr mPw ¼V t RTt where V ¼20 L/min, Pw ¼4 bar, m ¼16.043 g, R¼0.0820624 (1 atm/mol K) and T¼ 298 K. The density of the methane gas can be taken as r ¼2.57 g/L. The volume flow rate is then applied to the density to calculate a release rate of 51.45 g/min. The release transfer rate can then be set at 0.857 g/s. According to the U.K. Health and Safety Executive (HSE) hydrocarbon release classification system (HSE, 1999, 2003; UKOOA/HSE, 2006), the release rate for the jet fire tests can be classified as minor, from the possible options of major, significant, and minor, as indicated in Table 2. Table 1 LNG and LPG composition. LNG (%)

LPG (%)

CH4: 88.9 C2H6: 8.9 C3H8: 1.3

C3H8: 61.6 N2: 30.2 C4H10: 8.2

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2.1.4. Data acquisition The accurate measurement of the temperature around the steel and concrete tubular members is required to analyze the heat load. Fig. 4(a) shows a comparison of temperature versus time history as measured using a mercury thermometer, a sheathed thermocouple, and an exposed thermocouple placed in 100 1C boiling water. The sheathed thermocouple was chosen to measure the temperature because of its capacity to withstand temperatures of up to 1600 1C, as occuring in jet fires. A low-pass filter (LPF) was used to acquire data on the stable state. A low-pass filter is a filter that passes low-frequency signals, but attenuates (reduces the amplitude of) signals with frequencies higher than the cutoff frequency. The actual amount of attenuation for each frequency varies from filter to filter. The concept of a low-pass filter exists in many different forms, including electronic circuits (such as the hiss filters used in audio devices) and digital algorithms for the smoothing of data, acoustic barriers, and the blurring of images. Low-pass filters play the same role in signal processing as moving averages in fields such as finance: both tools provide a smoother form of a signal that removes the short-term oscillations, leaving only the long-term trend. The results with and without the LPF (30 Hz) for temperature versus time history are shown in Fig. 4(b) and (c). 2.1.5. Flame work To generate a jet flame, a high velocity of fuel release relative to the release diameter is required. Fig. 5(a) shows the torch (8 mm in diameter) used to release the methane gas. Fig. 5(b), (c), and (d) shows the shape of the fire created by different volume flow rates of 10, 15, and 20 L/min. The flame size was determined by using a standard configuration method. 2.1.6. Effect of wind The temperature distribution near a flame is easily affected by even light wind, although the shape of the jet fire is not affected. Accordingly, a wind barrier was erected around the jet fire test facility to minimize the wind effect (see Fig. 6). 2.2. Test overview

Fig. 3. Controlling volume flow rate with (a) control monitor and (b) controller.

Fig. 7 shows an overview of the fire test facility. The distance between the torch and tubular member was 300 mm. To optimize the shape of the jet fire, only 100% methane gas (20 L/min), released by a mass flow controller, was used. Twenty sheath thermocouples were used to obtain the temperature data at specific locations to evaluate the load characteristics. TDS-303 and Dewetron data loggers were used to store the temperature data by time and data on the shape of the flame, which was captured with a video camera. The gas release was terminated in the testing at 100 s, because after some 60 s the temperature on the tubes became a steady-state condition.

Table 2 HSE hydrocarbon release classification system. Classification

Major Significant Minor

Definition

Potential to quickly impact out of the local area causing serious injury or facilities Potential to cause serious injury or facility to personnel within the local area and to escalate within the local area Potential to cause serious injury to personnel in the immediate vicinity. But no potential to escalate or cause multiple facilities

Criteria Either

Or

4300 kg released

41 kg/s release rate and duration 45 min

Release rates between 0.1 and 1 kg/s lasting 2–5 min o 1 kg released

o0.1 kg/s release rate and duration o 2 min

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120

200 No LPF 160

80 60 40

Reference (mercury thermometer) Sheathed thermocouple

Temperature(K)

Temperature(K)

100

120 80 40

20

Sheathed thermocouple Exposed thermocouple

Exposed thermocouple

0

0 0

100

200

300 400 Time(s)

500

600

0

20

40 60 Time(s)

80

100

120

120

Temperature(K)

LPF: 30Hz 110

100

90 Sheathed thermocouple Exposed thermocouple

80 0

20

40

60 80 Time(s)

100

120

Fig. 4. (a) Comparison of temperature as measured by a sheathed thermocouple, an exposed thermocouple, and a mercury thermometer, (b) Comparison of temperature as measured by a sheathed thermocouple and an exposed thermocouple without LPF, and (c) Comparison of temperature as measured by a sheathed thermocouple and an exposed thermocouple with a LPF (30 Hz).

D= 8mm

Fig. 6. Photo of the wind barrier used for the jet fire tests.

Fig. 5. Methane gas released through a torch tip (a), with different flame shapes resulting from volume rates of (b) 10, (c) 15, and (d) 20 L/min.

and concrete tubular members. The thermocouples were exactly located 5 mm from the surface, and each section contained eight monitoring points (Fig. 8(b)). Symmetrical monitoring points were positioned in Sections B and B0 and Sections C and C0 to capture the non-linear characteristics of fire action.

2.3. Monitoring point

2.4. Test results and discussion

Fig. 8(a) shows the monitoring points in sections A, B, C, B0 , and C that were used to measure the temperature around the steel

The temperature versus time history obtained for each section in the jet fire tests on the steel and concrete tubular members

0

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Fig. 7. Layout of the jet fire test facility for steel and concrete tubular members.

200mm x 4 C

B

A

B

5

C 4

6 7

3 Fire direction

1140mm

8

2

for fire analysis. CFX can be applied to multiphase, heat transfer, radiation, and combustion fields with prismatic and tetrahedral elements. KFX can simulate all kinds of fires, fire impact, mitigation, and combustion using grid cell elements. Table 3 summarizes the types of CFD models applied for KFX and ANSYS CFX. The total simulation time of the CFX was one week and that of the KFX was three days, based on release duration of 600 s. 3.1. CFX simulation

1 Fig. 8. Monitoring points located on different sections: (a) side elevation and (b) plan view.

were compared. The results for Section A allow the easy identification of the heat load characteristics. The temperatures from the steel tubular member test were lower than those from the concrete tubular member test. This is due to the transfer of heat energy by conduction, which gives a lower temperature distribution. Fig. 9(a–c) shows the temperature versus time history at points 1, 2, 3, and 7 in Section A. The results suggest that it is possible to predict the temperature distribution of tubular members used in offshore and FPSO topsides fitted with passive fire protection (PFP). The temperature distribution with PFP is likely to be higher than without PFP. For the sections located far from the jet flame (C and C0 ), it was hard to analyze the heat load characteristics due to the low temperatures (see Fig. 10).

3. Computational fluid dynamics analysis A wide range of models are available for calculating fire dimensions and loads. There are several simple hand calculation models that are based on empirical data. At the other extreme, there are several computational fluid dynamics (CFD) software packages that allow very sophisticated calculations to be performed. To validate and verify the jet fire test results, the CFD codes Kameleon FireEx (KFX, 2007) and ANSYS CFX were used to conduct a numerical study with homogenous conditions. ANSYS CFX, (2008) is a widely used fluid analysis program, whereas KFX is special software

The domain size used in the CFX simulation was 4000  4000  3000 (x  y  z) mm, giving the domain shape shown in Fig. 11. The mesh consisted of tetrahedral elements, as shown in Fig. 11(b). The total number of nodes was 63,685 and the total number of tetrahedral elements was 353,812. The temperature distribution due to the rapid diffusion of jet fire in conditions of convection and radiation obtained at 0.02, 0.04, 0.1, 0.5, 1, and 5 s is shown in Fig. 12. 3.2. KFX simulation The domains used in the KFX simulation were xl( 0.8 m), xh(3.2 m), yl( 1.6 m), yh(2.4 m), zl(0 m), and zh(3 m), which gave a domain size of 4000  4000  3000 (x  y  z) mm and the domain shape depicted in Fig. 13 (as same as for the CFX simulation). Two types of grids for modeling fire action are included in KFX, i.e., a jet grid and a user predefined grid. In this simulation, the user predefined grid was applied due to the low release rate used. The mesh consisted of grid cells. The total number of nodes was 278,144. The temperature distribution obtained at 0.02, 0.04, 0.1, 0.5, 1, and 5 s is presented in Fig. 14. 3.3. CFD results and discussion Fig. 15 shows graphs of the temperature values averaged from 90 to 100 s and their convergence over time for every case. Fig. 15(a) shows the temperature versus time history for Section A. The solid line is the KFX result and the dotted line the CFX result. The triangle symbols denote the mean temperature from the concrete tubular member test and the square symbols denote the mean temperature from the steel tubular member test. Fig. 15(b)

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1200

Section A1

Test(Concrete) Test(Steel)

1200

Temperature(K)

Temperature(K)

1400

1000 800 600 400

Section A3

800 600 400 200

200 0

20

40 60 Time(s)

80

100

0

1200 Section A5

Test(Concrete) Test(Steel)

1000 800 600

20

40 60 Time(s)

Section A7

80

100

Test(Concrete) Test(Steel)

1000 Temperature(K)

1200 Temperature(K)

Test(Concrete) Test(Steel)

1000

800 600 400

400 200

200 0

20

40 60 Time(s)

80

100

0

20

40 60 Time(s)

80

100

Fig. 9. (a) Load characteristics of steel and concrete tubular members under jet fire expressed in temperature versus time history for section A1, (b) Load characteristics of steel and concrete tubular members under jet fire expressed in temperature versus time history for section A3, (c) Load characteristics of steel and concrete tubular members under jet fire expressed in temperature versus time history for section A5, and (d) Load characteristics of steel and concrete tubular members under jet fire expressed in temperature versus time history for section A7.

1200

Section C1

Table 3 Types of models applied in the numerical study.

Test(Concrete) Test(Steel)

Temperature (K)

1000

Modeling

ANSYS CFX method

Kameleon FireEx method

Turbulence Combustion

k-Epsilon model Eddy dissipation model P1 model Adiabatic

k-Epsilon model Eddy dissipation concept (EDC) model The discrete transfer model (DTM) Adiabatic

Tetrahedron

Porosity

None

Eddy dissipation concept (EDC) model

Radiation Wall heat transfer Sub-grid geometry Soot

800

600

400

200 0

20

40

60

80

100

Time (s) Fig. 10. Load characteristics of steel and concrete tubular members under jet fire expressed in temperature versus time history for section C1.

shows the temperature versus time history for Section B, Fig. 15(c) that for section B0 , and Fig. 15(d) that for Section C. The average temperature distribution from 90 and 100 s for each section was also plotted in a radial graph to determine the symmetry of the temperature results. The results from the jet fire tests show that the temperature at all symmetric points tended to be similar. However, the temperatures obtained from the CFD

Fig. 11. Extent of the analysis and mesh modeling of the ANSYS CFX model for the jet fire tests using tetrahedral elements.

B.J. Kim et al. / Ocean Engineering 37 (2010) 1159–1168

simulations appear to be more asymmetric. There are several reasons for this difference, including the composition of the element distance in the user defined mesh and the element size (Fig. 16).

4. Concluding remarks In this study, the load characteristics of steel and concrete tubular members under jet fire were determined. The results can

Fig. 12. Variation in temperatures with time at (a) 0.02 s, (b) 0.04 s, (c) 0.1 s, (d) 0.5 s, (e) 1 s, and (f) 5 s.

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be used in the design of passive fire protection (PFP) for application in offshore plant and floating production storage and offloading system (FPSO). Different load characteristics were identified and predicted for different materials, pipe diameters, and an equipment under jet fire. Although there was differential pressure in the mass flow controller, it was confirmed that the temperature distribution obtained by the CFD simulations was analogous to the experimental results. The convergence of the temperatures with the experimental results was evaluated at between 90 and 100 s to take into account the effect of conduction on the concrete tubular member. It is concluded that the CFD simulations can be an useful approach to predict jet fire loads in terms of temperature and heat flux. However, it is also important to realize that the CFD modeling technique must be relevant. Otherwise, the resulting computations could be totally wrong because those significantly depend on the modeling techniques. In the present study, one specific size of tubes which was similar to that of pipings in FPSO topsides was chosen in the fire testing program. Further studies are suggested to investigate the effect of different tube size on fire loads. Also, different types of tubes such as composite tubes or more realistic piping with or without passive fire protection (PFP) need to be considered. Buckling collapse testing of structures subject to external forces together with jet fire is also recommended.

zh(3m) 2420mm z

3m

r=150mm

x

y 840mm

1140mm

xh(3.2m)

zl(0m) yh(2.4m) 4m

4m

Leak point yl(-1.6m)

xl(-0.8m)

Fig. 13. KFX model for the jet fire tests using a grid.

Fig. 14. Variation in temperature with time at (a) 0.02 s, (b) 0.04 s, (c) 0.10 s, (d) 0.50 s, (e) 1.00 s, and (f) 5.00 s.

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1200

KFX(SectionA) CFX(SectionA) Test(Concrete) Test(Steel)

Section A A-1

1000

A-1

1200 Section B

KFX(SectionB) CFX(SectionB) Test(Concrete)

1000

A-2

200mm 4

4

800

Temperature(K)

Temperature(K)

C BABC A-3 A-3

600 200mm 4

C BABC

6 7

3 Fire 1140mm direction

2

Fire 1140mm direction

2

1

6 7 8

600

8

1

B-1

400

A-5 A-5

B-3 B-5

200

200 1.1

1.2

1.3 Height(m)

1.3 Height(m)

1.2

1.1

1.5

1.4

1200

Section B'

1000

200mm 4

4

6 7 8

3

800 Fire direction

1140mm

2

1

600 B'-1 400

1.5

200mm 4

C BABC

5 Temperature(K)

C BABC

1.4

KFX(SectionC) CFX(SectionC) Test(Concrete) Test(Steel)

Section C

KFX(SectionB') CFX(SectionB') Test(Concrete)

1000

Temperature(K)

3

800

A-4

5

4 400

5

4 3

800

Fire 1140mm direction

2

5

1

6 7 8

600

400

B'-3

C-1 C-1

B'-5 200

C-5 C-5

200 1.1

1.2

1.3 Height(m)

1.4

1.5

1.1

1200

1.2

1.4

1.5

KFX(SectionC') CFX(SectionC') Test(Concrete) Test(Steel)

Section C'

1000

200mm 4

C BABC 4 Temperature(K)

1.3 Height(m)

5 6 7

3

800

Fire 1140mm direction

2

1

8

600

400 C'-1 C'-1

C'-5 C'-5

200 1.1

1.2

1.3 Height(m)

1.4

1.5

Fig. 15. (a) Comparison of temperatures from the test measurements and the CFD simulations for section A, (b) Comparison of temperatures from the test measurements and the CFD simulations for section B, (c) Comparison of temperatures from the test measurements and the CFD simulations for section B’, (d) Comparison of temperatures from the test measurements and CFD simulations for section C, and (e) Comparison of temperatures from the test measurements and CFD simulations for section C’.

B.J. Kim et al. / Ocean Engineering 37 (2010) 1159–1168

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A-5

B-5

A-6

A-4

A-3

0

CFD (KFX) CFD(CFX) Test(Concrete) Test(Steel inside)

A-7 300 600 900 1200 Temperature (K)

A-2

B-6

B-4

CFD (KFX) CFD(CFX) Test(Concrete) Test(Steel outside) Test(Steel inside) B-3

A-8

0

300

B-7 600 900 1200 Temperature (K)

B-2

B-8

A-1

B-1

B'-5

C-5

B'-4

B'-6

C-4

CFD (KFX) CFD(CFX) Test(Concrete) Test(Steel inside)

C-6

B'-7 B'-3

0

B'-2

300

C-3

900 1200 Temperature (K)

600

B'-8

0

300

600

C-2

CFD(KFX) CFD(CFX) Test (Concrete) Test (Steel outside) Test (Steel inside)

C-7 900 1200 Temperature(K)

C-8

B'-1

C-1 C'-5

C'-4

C'-6

CFD(KFX) CFD(CFX) Test (Concrete) Test (Steel outside) Test (Steel inside) C'-7

C'-3

0

C'-2

300

600

900 1200 Temperature(K)

C'-8

C'-1 Fig. 16. (a) Comparison of temperatures from the test measurements and CFD simulations for section A, (b) Comparison of temperatures from the test measurements and CFD simulations for section B, (c) Comparison of temperatures from the test measurements and CFD simulations for section B’, (d) Comparison of temperatures from the test measurements and CFD simulations for section C, and (e) Comparison of temperatures from the test measurements and CFD simulations for section C’.

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Acknowledgments This study was undertaken at the Lloyd’s Register Educational Trust (LRET) Research Centre of Excellence at Pusan National University, Korea. The results are part of Phase II of the Joint Industry Project on Explosion and Fire Engineering of FPSOs (EFEF JIP). The authors are pleased to acknowledge the support of the partners involved in the EFEF JIP, including Pusan National University (Korea), Hyundai Heavy Industries (Korea), Daewoo Shipbuilding and Marine Engineering (Korea), American Bureau of Shipping (USA), Nowatec AS (Norway), Health and Safety Executive (UK), ComputIT (Norway), and Gexcon (Norway). This work was also supported by the National Research Foundation (NRF) grant funded by the Korea Government (MEST) (Grant no.: K20901000005-09E0100-00510). This paper was presented at OMAE 2010 Conference, 6–11 June 2010, Shanghai, China.

References Alvaro, B., Emilio, L., Silvia, B.S., Jacqueline, B.S., 2001. Contingency Planning for Oil Spill Accidents in Brazil. UFRJ, Brazil. ANSYS CFX, 2008. release 11.0, ANSYS Inc., Canonsburg, PA, USA. Cullen, L., 1990. The Public Inquiry into the Piper Alpha Disaster. HMSO, London, UK.

Czujko, J., 2001. Design of Offshore Facilities to Resist Gas Explosion Hazard: Engineering Handbook. CorrOcean, Oslo, Norway. Czujko, J., 2005. Computational methods in the analysis of explosion resistant barriers. In: Proceedings of International Conference on Computational Methods in Marine Engineering, Norway. Czujko, J., 2007. Consequences of explosions in various industries. Safety and reliability of industrial products, systems and structures, In: Proceedings of the SAFERELNET. FABIG, 2009. Technical Note II: Fire Loading and Structural Response. Berkshire, UK. HSE, 1999. Review of Analysis of Explosion Response, Health and Safety Executive report—OTO 98174, London, UK. HSE, 2003. Fire and Explosion Guidance, Part 1: Avoidance and Mitigation of Explosions, Health and Safety Executive, London, UK. KFX, 2007. User’s Manual of Kameleon FireEx, ComputIT Inc., Stavanger, Norway. Nolan, D.P., 1996. Handbook of Fire and Explosion Protection Engineering Principles for Oil, Gas, Chemical, and Related Facilities. Noyes Publications, Westwood, NJ, USA. Paik, J.K., 2010. Explosion and Fire Engineering of FPSOs (Phase II) Definition of Fire and Gas Explosion Design Loads, Final Report of EFEF JIP (Phase II), Research Institute for Ship and Offshore Structural Design Innovation. Pusan National University, Busan, Korea. Paik, J.K., Czujko, J., 2009. Explosion and Fire Engineering of FPSOs (Phase I), Final Report of EFEF JIP (phase I). Research Institute for Ship and Offshore Structural Design Innovation, Pusan National University, Busan, Korea. Paik, J.K., Thayamballi, A.K., 2003. Ultimate Limit State Design of Steel-Plated Structures. John Wiley & Sons, Chichester, UK. Paik, J.K., Thayamballi, A.K., 2007. Ship-Shaped Offshore Installations: Design, Building, and Operation. Cambridge University Press, UK. UKOOA/HSE, 2006. Fire and Explosion Guidance (part 2): Avoidance and Mitigation of Fires, Offshore Operators Association/Health and Safety Executive, London, UK.