Numerical investigation of LNG gas dispersion in a confined space: An engineering model
Tóm tắt
The present study has numerically investigated a dynamic methane leak and dispersion in a confined space. To establish a numerical prediction based engineering model of dynamic gas leak and dispersion in a confined space, numerical experiments are conducted for variation of a key parameter–leak hole size. Based on the numerical results data, an engineering model is developed. The parameters related to lower flammable limit of the methane were quantitatively analyzed to compare the potential risk due to a gas leak. To quantitatively investigate the flammable region, the longitudinal and transverse directional length is defined and studied. We found that the ratio between longitudinal and transverse directional length can be a bridge to model the flammable region. The aspect ratio of the flammable region is fitted by an exponential function to show the relation with time. Then, an oval-shape model is presented to predict flammable region. Oval-shape model is completed by the combination of aspect ratio relation and a function for transverse length. Finally, we compared the developed engineering model (oval-shape model) and numerical results. The engineering model can predict the flammable region quite well when it reaches steady state. It is expected that the established engineering model is valuable for the Quantitative risk assessment (QRA), initial emergency strategy preparation when a fuel gas leak accident happened in a Combined cycle power plant (CCPP). We hope it is also can be a kind of data base for power plant operation manual.
Tài liệu tham khảo
O. R. Hansen, F. Gavelli, M. Ichard and S. G. Davis, Valida tion of FLACS against experimental data sets from the model evaluation database for LNG vapor dispersion, J. of Loss Prevention in the Process Industries, 23 (2010) 857–877.
A. L. Polyzakis, Optimum gas turbine cycle for combined cycle power plane, Energy Conversion and Management, 49 (2008) 551–563.
A. Poulikas, An overview and future sustainable gas turbine technologies, Renewable Sustainable Energy Reviews, 9 (2009) 409–443.
J. H. Juo, M. Zheng, X. W. Zhao, C. Y. Huo and L. Yang, Simplified expression for estimating release rate of hazardous gas from a hole on high-pressure pipelines, J. of Loss Prevention in the Process Industries, 19 (2006) 362–366.
Y. Jo and B. J. Ahn, A method of quantitative risk assessment for transmission pipeline carrying natural gas, J. of Hazardous Materials, 123 (2005) 1–12.
Y. Jo and B. J. Ahn, A simple model for the release rate of hazardous gas from a hole on high-pressure pipelines, J. of Hazardous Material, 97 (2003) 31–46.
D. Yuhu, G. Huilin, Z. Jing’en and F. Yaorong, Mathematical modeling of gas release through holes in pipelines, Chemical Engineering J., 92 (2003) 237–241.
D. Zhu, Example of simulating analysis on LNG leakage and dispersion, Procedia Engineering, 71 (2014) 220–229.
G. Dong, L. Xue and Y. Yang, Evaluation of hazard range for the natural gas jet released from a high-pressure pipeline: a computational parametric study, J. of Loss Prevention in the Process Industries, 23 (2010) 522–530.
I. Yet-Pole, C. M. Shu and C. H. Chong, Applications of 3D QRA technique to the fire/explosion simulation and hazard mitigation within a naphtha-cracking plant, J. of Loss Pre-vention in the Process Industries, 22 (2009) 506–515.
S. Dan, C. J. Lee, J. Park, D. Shin and E. S. Yoon, Quantita-tive risk analysis of fire and explosion on the top-side LNG-liquefaction process of LNG-FPSO, Process Safety and Environmental Protection, 92 (2014) 430–441.
K. H. Sung, J. W. Bang, L. Li, J. Choi, D. Kim, H. S. Ryou, K. B. Yoon and S. H. Lee, Effect of crack size on gas leakage characteristics in a confined space, J. of Mechanical Science and Technology, 30 (2016) 3411–3419.
K. P. Kim, H. K. Kang, C. H. Choung and J. H. Park, On the application of CFD codes for natural gas dispersion and ex-plosion in gas fuelled ship, J. of the Korean Society of Marine Engineering, 35 (2011) 946–956.
B. Sun, R. P. Utikar, V. K. Pareek and K. Guo, Computational fluid dynamics analysis of liquefied natural gas dispersion for risk assessment strategies, J. of Loss Prevention in the Process Industries, 26 (2013) 117–128.
ANSYS FLUENT Inc., FLUENT 13.0 User’s Guide (2014).
M. J. Assael and K. E. Kakosimos, Fires, explosion, and toxic gas dispersions: Effects calculation and risk analysis, CRC Press (2010).
Y. Zhao, L. Xihong and L. Jianho, Analysis on the diffusion hazards of dynamic leakage of gas pipeline, Reliability Engineering and System Safety, 92 (2007) 47–53.
E. Kim, K. Lee, J. Kim, Y. Lee, J. Park and I. Moon, Development of Korean hydrogen fueling station codes through risk analysis, International J. of Hydrogen Energy, 56 (2011) 13122–13131.
E. Kim, J. Park, J. Cho and I. Moon, Simulation of hydrogen leak and explosion or the safety design of hydrogen fueling station in Korean, International J. of Hydrogen Energy, 38 (2013) 1737–1743.
A. Luketa-Hanlin, A review of large-scale LNG spills: Ex periments and modeling, J. of Hazardous Materials, 132 (2006) 119–140.
R. B. Cormier, R. Qi, G. Yun, Y. Zhang and M. S. Mannan, Application of computational fluid dynamics for LNG vapor dispersion modeling: A study of key parameters, J. of Loss Prevention in the Process Industries, 22 (2009) 332–352.
J. Yu, V. Vuorinen, O. Kaario, T. Sarjovaara and M. Larmi, Visualization and analysis of the characteristics of transitional underexpanded jets, International J. of Heat and Fluid Flow, 44 (2013) 140–154.
W. R. Hawthorne, D. S. Weddell and H. C. Hottel, Mixing and combustion in turbulent gas jets, Symposium on Combustion and Flame, and Explosion Phenomena, 3 (1948) 266–288.