DOI QR코드

DOI QR Code

Numerical Model of Heat Diffusion and Evaporation by LNG Leakage at Membrane Insulation

LNG 화물창 방열재 균열에 따른 액화천연가스의 확산 및 온도 예측을 위한 수치 모델

  • Received : 2014.08.19
  • Accepted : 2014.12.18
  • Published : 2014.12.31

Abstract

The leakage of cryogenic LNG through cracks in the insulation membrane of an LNG carrier causes the hull structure to experience a cold spot as a result of the heat transfer from the LNG. The hull structure will become brittle at this cold spot and the evaporated natural gas may potentially lead to a hazard because of its flammability. This paper presents a computational model for the LNG flow and heat diffusion in an LNG insulation panel subject to leakage. The temperature distribution in the insulation panel and the speed of gas diffusion through it are simulated to assess the safety level of an LNG carrier subject that experiences a leak. The behavior of the leaked LNG is modeled using a multiphase flow that considers the mixture of liquid and gas. The simulation model considers the phase change of the LNG, gas-liquid multiphase interactions in the porous media, and accompanying rates of heat transfer. It is assumed that the NO96-GW membrane storage is composed of glass wool and plywood for the numerical simulation. In the numerical simulation, the seepage, heat diffusion, and evaporation of the LNG are investigated. It is found that the diffusion speed of the leakage is very high to accelerate the evaporation of the LNG.

Keywords

Two-phase/Multiphase flow;Porous media;LNG leakage;BOR (boil-off-ratio);LNG cargo containment;Evaporation

References

  1. Aungier, R.H., 1995. A Fast, Accurate Real Gas Equation of State for Fluid Dynamic Analysis Applications. Journal of Fluids Engineering, 117, 277-281. https://doi.org/10.1115/1.2817141
  2. Bae, J., Joh, K., Yoon, H., Lee, H., and Ha, M., 2007. Safety Evaluation of Mark III Type LNG Carriers under Barrier Leakages. Proceedings of 15th International Conference of Liquefied Natural Gas, PS6-2.1.
  3. Caps, R. and Fricke, J., 2000. Thermal Conductivity of Opacified Powder Filler Materials for Vacuum Insulations 1. International Journal of Thermophysics, 21(2), 445-452. https://doi.org/10.1023/A:1006691731253
  4. Choi, I., Yu, Y.H., and Lee, D.G., 2013. Cryogenic Sandwich-Type Insulation Board Composed of E-Glass/Epoxy Composite and Polymeric Foams. Composite Structures, 102, 61-71. https://doi.org/10.1016/j.compstruct.2013.02.017
  5. Choi, S.W., Roh, J.U., Kim, M.S., and Lee, W.I., 2012. Analysis of Two Main LNG CCS (Cargo Containment System) Insulation Boxes for Leakage Safety using Experimentally Defined Thermal Properties. Applied Ocean Research, 37, 72-89. https://doi.org/10.1016/j.apor.2012.04.002
  6. Chu, B., Chang, D., and Chung, H., 2012. Optimum Liquefaction Fraction for Boil-off Gas Reliquefaction System of Semi-Pressurized Liquid CO2 Carriers Based on Economic Evaluation. International Journal of Greenhouse Gas Control, 10, 46-55. https://doi.org/10.1016/j.ijggc.2012.05.016
  7. Colson, D., Haquin, N., Malochet, M., 2012. Reduction Of Boil-Off Generation In Cargo Tanks Of Liquid Natural Gas Carriers - Recent Developments Of Gaztransport & Technigaz (GTT) Cargo Containment Systems, World Gas Conference.
  8. Demharter, A., 1998. Polyurethane Rigid Foam, a Proven Thermal Insulating Material for Applications between $+130^{\circ}C$ and $-196^{\circ}C$. Cryogenics, 38(1), 113-117. https://doi.org/10.1016/S0011-2275(97)00120-3
  9. Vanem, E., Antao, P., Ostvikc, I., de Comas, F.D., 2008. Analysing the Risk of LNG Carrier Operations. Reliability Engineering & System Safety, 93(9), 1328-1344. https://doi.org/10.1016/j.ress.2007.07.007
  10. GTT, 2014. Retrieved on J. Available at: [Accessed 6 Jan. 2014]
  11. Hasan, M.M.F., Zheng, A.M., Karimi, I.A., 2009. Minimizing Boil-off Losses in Liquefied Natural Gas Transportation. Industrial & Engineering Chemistry Research, 48(21), 9571-9580. https://doi.org/10.1021/ie801975q
  12. Hwang, S.Y., Lee, J.H., Kim, S.C., 2012. Simplified Impinging Jet Model for Practical Sloshing Assessment of LNG Cargo Containment. Proceedings of the Twenty-second International Offshore and Polar Engineering Conference, ISOPE, Rhodes, Greece, 495-501.
  13. Qi, R., Ng, D., Cormier, B.R., Mannan, M.S., 2010. Numerical Simulations of LNG Vapor Dispersion in Brayton Fire Training Field Ttests with ANSYS CFX. Journal of Hazardous Materials, 183, 51-61. https://doi.org/10.1016/j.jhazmat.2010.06.090
  14. Ito, H., Suh, Y.S., Chun, S.E., Satish Kumar, Y.V., Ha, M.K., Park, J.J., Yu, H.C., Wang, B., 2008. A Direct Assessment Approach for Structural Strength Evaluation of Cargo Containment System under Sloshing Inside LNGC Tans based on Fluid Structure Interaction. Proceeding of 27th Int Conf on Offshore Mech and Arctic Eng, Estoril, Portugal, 5, 835-845.
  15. Kim, B.G., Lee, D.G., 2008. Leakage Characteristics of the Glass Fabric Composite Barriers of LNG Ships, Composite Structures, 86, 27-36.
  16. Lee, H.B., Park, H.J., Rhee, S.H., Bae, J.H., Lee, K.W., Jeong, W.J., 2011a. Liquefied Natural Gas flow in the Insulation Wall of a Cargo Containment System and its Evaporation. Applied Thermal Engineering, 31, 2605-2615. https://doi.org/10.1016/j.applthermaleng.2011.04.028
  17. Lee, S.J., Yang, Y.S., Kim S.C., Lee, J.H., 2011b. Strength Assessment Procedure of LNG CCS under Sloshing Load Based on the Direct Approach. Proceedings of the International Offshore and Polar Engineering Conference, ISOPE, Hawaii, USA, 183-190.
  18. Li, Y., Jin, G., Zhong, Z., 2012. Thermodynamic Analysis-Based Improvement for the Boil-off Gas Reliquefaction Process of Liquefied Ethylene Vessels. Chemical Engineering & Technology, 35(10), 1759-1764. https://doi.org/10.1002/ceat.201200019
  19. Livingston, M., Gustafson, R., 2009. Minimize Risks from Cryogenic Exposure on LNG Facilities. Hydrocarbon Processing, 88(7), 51-58.
  20. Nho, I.S., Kim, S.C., Jang, B.S., Lee, J.H., 2012. Parametric Investigation on the Simplified Triangular Impulse of Sloshing Pressure and Categorization of the Structural Response on the Mark III LNG CCS, Proceedings of the Twenty-second International Offshore and Polar Engineering Conference, ISOPE, Rhodes, Greece, 495-501.
  21. Presley, M.A., Christensen, P.R., 1997. Thermal Conductivity Measurements of Particulate Materials 1. A Review, Journal of Geophysical Research, 102(E3), 6535-6549. https://doi.org/10.1029/96JE03302
  22. Ranz, W.E., Marshall, W.R., 1952. Evaporation from Drops. Chemical Engineering Progress, 48(3), 141-146.
  23. Shin, Y., Lee, Y.P., 2009. Design of a Boil-off Natural Gas Reliquefaction Control System for LNG Carriers, Applied Energy, 86(1), 37-44. https://doi.org/10.1016/j.apenergy.2008.03.019
  24. Zakaria, M.S., Osman, K., Saadun, M.N.A., Manaf, M.Z.A., Hanafi, M.H.M., 2013. Computational Simulation of Boil-off Gas Formation inside Liquefied Natural Gas Tank using Evaporation Model in ANSYS Fluent. Applied Mechanics and Materials, 393, 839-844. https://doi.org/10.4028/www.scientific.net/AMM.393.839

Cited by

  1. Experimental Study on Correction of Thermal Conductivity Obtained by Heat Flow Method using Commercial Guarded Hot Plate Method Apparatus vol.29, pp.2, 2015, https://doi.org/10.5574/KSOE.2015.29.2.169
  2. Measurement of Real Deformation Behavior in C-type Lng Mock-up Tank using Strain Gage vol.30, pp.2, 2016, https://doi.org/10.5574/KSOE.2016.30.2.117