Year: 2017 Volume: 1 Issue: 1 Page: 19-24
PARAMETRIC STUDY ON LNG VAPORIZER WITH AIR, WATER AND STEAM AS HEATING MEDIA
Natural gas, in the liquid form takes up about 1/600th the volume of its gaseous state, which provides a cost-effective means to transport natural gas from the sources of supply to the available markets. This Liquefied Natural Gas (LNG) is used in medium and heavy-duty vehicles. The liquefied natural gas is pumped out of the storage tanks and the system includes means for transferring heat from the heating fluid to the LNG so that it returns to its natural gaseous state. The natural gas is then pumped in to the natural gas transmission system, and supplied to the market. This vaporizer for LNG comprises of a Kettle reboiler for total vaporization and a Shell and Tube heat exchanger as super heater to attain the delivery pressure for natural gas. The heat transfer coefficients were maximized for the process fluids so that the shell side and tube side pressure drops are kept within permissible limits. The optimum design of LNG vaporizers is a tedious job. To overcome this, a Visual Basic program was developed using various correlations and equations, and the results obtained were validated with HTRI. Design was carried out for all the three fluids; air, water and steam. For a given heat duty of vaporizer, characteristics curves for both tube side and shell side were generated for various tube materials and tube sizes.On basis of these characteristics, the variation of tube side and shell side could be easily compared and hence the design can be finalized for particular requirement or application.
Anahtar Kelimeler (Keywords): Liquefied Natural Gas (LNG), Vaporizer, Re-gasification, Kettle Reboiler, Air, Water, Steam