Structural Design And Strength Analysis Of Liquefied-Gas Cryogenic Tanks

With the development of national economics, liquefied-gas are getting more and more widely used in many fields, especially in agriculture, industry, scientific research and medical areas. Vertical liquefied-gas cryogenic tanks are the major equipment to store and transport liquefied-gas. To meet the increased needs of liquefied-gas, diversified vertical liquefied-gas cryogenic tanks are required, which calls for more safe and reasonable structures. In the thesis, several forms liquefied-gas cryogenic tanks are taken into consideration for the strength, stiffness and structural study.(1) For the vertical liquefied-gas cryogenic tanks, a numerical simulation is studied based on solid modeling and ANSYS Workbench. With this method, the modeling can be better parameterized, structural and model modification can be more easily performed and boundary constrain can be more reasonably applied according the load case. Stress analysis and strength check for several vertical liquefied-gas cryogenic tanks show that this method is accurate and applicable.(2) A simple design method was proposed in order to decrease thermal stress in the cryogenic tanks. To prove this method, finite element analysis was also carried out. Results show that the proposed method is effective and can be used in the engineering design of cryogenic tanks.(3) The vertical liquefied-gas cryogenic tanks with special design to eliminate the thermal stress are numerically studied. Results show that without the thermal stress, the vertical liquefied-gas cryogenic tanks can be designed with relatively light-weight.(4) Two kinds of vertical liquefied-gas cryogenic tanks with different supporters, namely skirt supporter and leg supporter, were studied and compared. Results show that for most load cases, the skirt supporter is superior in strength and stiffness to the leg supporter. But the skirt supporter itself consumes more materials and thus, may cost higher. So it is suggested that for larger cryogenic tanks, skirt supporter is a better choice while for small or medium cryogenic tanks, it is better to use leg supporter.