Elimination of fog formation during ambient air regasification of liquefied natural gas

摘要

A system and method for regasifying LNG using ambient air vaporizers without ambient air fog formation. The warm moist ambient air is cooled and dried using cold recovery from the cryogenic LNG stream by means of an intermediate heat transfer fluid circulated in a closed loop followed by the addition of a warm diluent air stream such that the final temperature of the exit stream of mixed air is at or above the ambient air dew point. Adjustable diluent air dampers permit an induced draft ambient vaporizer assembly.

主权项

1. A process for vaporizing cryogenic fluids and liquefied natural gas using only ambient air heat without producing ambient air fog comprising:
a. inducing a flow of warm ambient intake air from a warm ambient air supply to a vaporizer air intake air dryer having heat transfer elements and adapted to condense and remove moisture from said flow of warm ambient intake air, b. providing said dryer with a stream of intermediate heat transfer cooling fluid, said cooling fluid flowing within said heat transfer elements of said air dryer, c. cooling said ambient intake air in said air dryer to produce cooled intake air having condensed moisture therein, d. separating said condensed moisture from said cooled intake air and discharging said moisture from the process, e. passing said cooled ambient intake air through an induced draft ambient air vaporizer having a plurality of heat transfer elements, f. further cooling and drying said ambient intake air in said ambient air vaporizer to produce a further cooled air stream, g. passing said further cooled air stream out of said vaporizer and collecting said further cooled air in an exit air discharge duct, h. conveying said further cooled air stream to a mixing zone, i. admitting a warm ambient diluent air side stream of said warm ambient air to said mixing zone and mixing said side stream with said further cooled and dried air stream such that the mixed air resulting therefrom has a temperature which is at or above the dew point of said warm ambient air supply, j. discharging said mixed air from said discharge duct through a discharge induced draft fan, and k. passing preheated cryogenic fluid to be vaporized thru said induced draft ambient air vaporizer to vaporize and super heat said cryogenic fluid whereby no ambient air fog is produced while vaporizing cryogenic fluids using only said ambient air in the vaporizer.