Thermal analysis of LNG storage tank for LNG bunkering system

Title & Authors
Thermal analysis of LNG storage tank for LNG bunkering system
Yun, Sang-kook;

Abstract
In 2016, the IMO's new rules for an 80% reduction in NOx emissions in newly built ships will necessitate the use of LNG as a clean fuel. So far, the developed European countries have led the development of LNG bunkering ships and related facilities. An LNG bunkering system stores LNG in a horizontal or vertical IMO "C"-Type tank insulated with perlite powder, and a vacuum in the annular space between the double walls, like the cryogenic liquid nitrogen tank. Current storage tanks have high heat leakage, evaporating over 2.0% daily, and are difficult to build with the required vacuum. A more efficiently insulated storage tank could reduce the evaporation rate. This research carried out thermal analysis on a new effective insulation method that separates high vacuum in the annular space between two tanks with a solid insulation material, such as urethane foam, lining the outer vessel. This highly efficient insulation system obtained an evaporation rate of 0.03% per day under a $\small{10^{-3}torr}$ vacuum, and an evaporation rate of 0.11% at $\small{10^{-45}torr}$. Even if the space loses its vacuum, the new insulation system showed a lower evaporation rate of 4.12% than the present perlite system of 4.9%. This newly developed tank can increase the efficiency of LNG storage tank and may help keep LNG bunkering systems safe.
Keywords
LNG bunkering;Double-walled tank;Insulation material;Vacuum perlite;High vacuum;Urethane foam;
Language
Korean
Cited by
1.
A Study on the Development of Educational Programs for LNG Bunkering in Consideration of the Safety System, Journal of the Korean Society of Marine Environment and Safety, 2016, 22, 3, 268
References
1.
Regulation-13,http://www.imo.org/en/OurWork/Environment/PollutionPrevention/AirPollution/Pages/Nitrogenoxides, Accessed August 10, 2015.

2.
News, Muhwa Ilbo, http://www.munhwa.com/news/view.html?no=2013071601071343054002, Accessed July 16, 2013.

3.
News, Energy & Environment News Plus, http://www.e2news.com/news/articleView.html?idxno=82507, Accessed July 15, 2015.

4.
Swedish Maritime Technology Forum, "LNG ship to ship bunkering procedure," 2013.

5.
R. Thomas and H. Patel, Design and Certification of "Type C" Independent Tanks for Gas Fueled Ships, ASME-USCG Workshop, 2013.

6.
T. W. Kim, Y. S. Suh, K. B. Jang, and K. H. Cha, "A study and design on tank container for fuel tank of LNG fueled ship," Journal of the Society of Naval Architects Engineering, vol. 46, no. 6, pp. 504-511, 2012 (in Korean).

7.
S. B. Shin, D. J. Lee, D. H. Kim, and H. S. Kim, "A study on Design of IMO C type Fuel Storage Tank with Capacity of 500 \$m^3\$, Proceedings of the Twenty-third International Offshore and Polar Engineering, ISOPE, ISBN 978-880633-99-9, pp. 846-854, 2013.

8.
R. F. Barron, Cryogenic Systems, 2nd ed., NewYork, USA: Oxford University Press, 1985.

9.
L. Jin, C. Lee, J. Park, and S. W. Jung, "Prediction of the effective thermal conductivity of powder insulation," Proceedings of the 25th International Cryogenic Engineering Conference, pp. 1-6, 2014.