Design and Analysis of Refrigerated Liquefied Gas Transport Container

Abstract

Atmospheric gases like N2, Ar, O2, N2O, C2H4, C2H6 and R−23 are always transported in liquidized form for bulk of transportation. To liquidized atmospheric gases, gases are pressurized and stored at refrigerated temperature. These pressurized liquids are stored transported in cryogenic containers. To maintain these substances liquidized, container has been designed for−196C temperature and 1.654MPa internal pressure. Cryogenic container is a double wall pressurized vessel fitted inside frame. The whole system consists of inner vessel for storage of cryogenic substance, evacuated Outer jacket to provide insulation and to isolate inner vessel from atmosphere, Support system for connecting inner vessel to outer jacket and to absorb various loads applying on inner vessel due to transportation and frame structure for handling and easy transportation. For insulation purpose aluminum foil is wrapped around inner vessel and vacuum is generated between inner vessel and outer jacket. Various international codes such as ASME, IMDG and CGA-341 have been complied for designing of container. Design of inner vessel has been carried out using cold stretched material to increase material’s allowable stress limit and to reduce thickness. Outer jacket has been designed based on ambient condition. Discontinuity stresses generated at head-shell junction have been determined. The project covers the mechanical design calculations of inner vessel and outer vessel using ASME Section VIII Division 1 and CGA-341, Specifications for Insulated Cargo Tank for Non flammable Cryogenic Liquids respectively. Sizing of safety relief valve for inner as well as outer vessel has been determined based on hazardous condition. Terminologies like net evaporation rate, holding time related to support system have been determined. Finite element analysis has been done for inner vessel as well as outer jacket for internal and external pressure respectively. Inner vessel is supported to outer vessel by axial and circumferential supports. Support system design has been determined by using composite material for insulation purpose. Frame has been provided for stability and handling purpose. Frame has been designed based on standard vertical load mentioned in ISO standards. Finite element analysis has also been done for frame. Saddles have been designed to sustain weight of container.