Research On Non-destructive Storage Of LNG Tank Container

In China,the traditional modes of LNG transporting include using LNG bulk ships on sea and using LNG tank vehicles on land,these modes have the common disadvantages of potential safety hazards,low economic benefit,complicated transportation process,investment and construction period long,etc.The LNG tank container can be transported directly by the general container ship,and the standardized LNG tank container also suitable for the multimodal transport mode of road and railway.This mode realize the seamless connection between the production and marketing,which calls "door to door" and "a tank of all".It also save the plurality of storage,loading and unloading links in the traditional transportation mode;eliminate the potential safety hazards in the process of multimodal transportation.Meanwhile,the LNG tank container mode has the advantages of low construction investment,well transportation maneuverability,efficient loading and unloading operation;these make up the disadvantages of the traditional transportation mode.In addition,although the LNG tank container is designed and manufactured as means of transport,it also functions as the storage vessel,the sales vessel and the like.Therefore,under certain conditions or transport modes,LNG tank containers have a strong development prospect.LNG tank container belongs to the pressure vessel for carrying the ultra-low temperature,inflammable and explosive liquefied gas.It is an so important danger source which need be paid attention during the process of ship transportation.This paper briefly analyze the four main danger sources of LNG tank container during ship transportation,by establishing the risk matrix to identify the risk degree of each danger source,put forward the management and operation suggestions.In the process of risk identification,the risk of flammable gas accumulation is extremely high,which is an important concern affecting the safety of LNG tank container transportation.The main cause of flammable gas accumulation is the non-destructive storage state of LNG tank container,safety valve exhaust and release pressure to cause gas accumulation,the paper found that the non-destructive storage of the LNG in the container is an important technical problem which guarantee the safety of the LNG tank container during the ship transportation.Therefore,based on the design parameters of LNG tank container,the physical properties of LNG,the non-destructive storage process of LNG in tank container is analyzed and studied detailly in this paper.The insulation performance is an important factor which affect the pressure rising in the inner tank,this paper analyze the heat transferring process of LNG tank container,research the influencing factors and relationship of the daily evaporation rate in LNG tank container.On this basis,the saturated homogeneous model and Russian model are combined and modified to establish a calculation model suitable for calculating the holding time of LNG tank containers which under different external environment,different filling rate and other different initial conditions.This model solves the using limitation of referenoe curve provided by manufacturer and provides reference for the overall logistics planning and the filling rate of LNG tank container.At the same time,the operator on ship can effectively start the operation to keep safety according to the pressure-up of the LNG tank container and the opening condition of the safety valve,so as to avoid safety accidents caused by misoperation.