LNG Storage And Transportation System Of The Craft
LNG is the abbreviation of LNG, LNG is the main component of methane, it is natural gas after purification (dehydration, de-hydrocarbon, LNG Storage And Transportation System deacidification gas), the use of throttle, expansion and external cooling process of methane to form a liquid of. Since the volume of LNG is about 1/600 of its gaseous volume and the weight of LNG is only about 45% of the volume of water, LNG can quickly mix with air in the event of a large amount of leakage to reach the explosion limit.
LNG storage tanker tankers are currently vacuum powder insulated horizontal jacket containers, double structure, from the liner and shell made of. Inside and outside the tank connection using glass steel bolts fastening connection, the rear support for the fixed connection, the front bearing for the sliding connection to compensate for changes in temperature caused by tank expansion. The jacket is filled with expanded perlite and evacuated, and the exhaust pipe, exhaust pipe and so on are drawn from the inner container. The vacuum jacket leads to the bottom of the shell and is connected with the pipeline operating system. The liquid tank is fixed by U-shaped vice beam On a car chassis.
LNG transport tanker common types of accidents can be divided into rollovers, collision, cut rub, rear-end and other four categories. Among them, the rollover, LNG Storage And Transportation System collision and rear-end accidents in all types of road transport tanker accidents accounted for a higher proportion, usually on the tank and its tail valve will cause serious damage, resulting in the highest probability of leakage. As the structure of the tanker and the production of special materials, in particular, its outer protective shell and ring beams are mostly made of high compressive strength of carbon steel material composition, under normal circumstances, the outer shell damage, fracture accident The At present, a variety of information shows that there is no such situation at home and abroad, the vast majority of accidents are the tank shell of the various gas and pipe fittings, LNG Storage And Transportation System safety devices and joints at the fracture and leakage.
LNG tank special internal and external gallbladder and vacuum sandwich structure, determines its in the general state of the accident, the tank body is likely to occur directly leaks, and the pressure inside the tank due to various factors caused by overpressure caused by safety valve leakage Pressure or the accident led to the collapse of the tank shell, vacuum insulation layer of the role of insulation, the tank of LNG rapid heat absorption vaporization, resulting in internal pressure surge, the vacuum jacket in the pressure rose to 0. 02 ~ 0 07 MPa, the fuse will automatically open, the pressure relief. Because LNG has a narrow combustion range, LNG Storage And Transportation System high spontaneous combustion temperature (450 ℃), and easy to spread than the air characteristics, therefore, after the occurrence of leakage, the first priority is to prevent the occurrence of deflagration, LNG Storage And Transportation System do a good job of leakage of gas to disperse, Valve) work, find out the location of the leak, select the correct plugging method. Should be the most possible to create conditions, plugging, to reduce the cost of rescue, a multiplier effect.