Strength Analysis And Anti-Wave Plate Design Of A Liquefied Gas Tanker

In modern life and industrial production, liquefied gases are more and more widely used. Equipment for the transportation of these inflammable and even toxic gases is call movable pressure vessels, among which liquefied gas tanker is the major form and is used more and more as it has larger capability in load-carrying, lower cost in transportation. As undergoing unstable loadings in transportation, the tanker must be designed and fabricated strictly conformed to relevant technical requirements to ensure the safety in operation. Meanwhile, in order to increase the amount of medium, loadings on the tanker should be reasonably determined and the weight of the tanker itself should be decreased as much as possible. In this thesis, these aspects are addressed by performing strength analysis and liquid sloshing simulation of a liquefied gas tanker.Firstly, a finite element model was established with the software of ANSYS for the liquefied gas tanker in transportation on a semi-trailer. Stress analysis and strength check for the liquefied gas tanker in transportation on a semi-trailer are carried out using finite element method. It is found that strength requirements in some local places cannot be satisfied and the situation is not effectively improved if merely increasing the thickness of the reinforcement rings. The reason is the structure of the reinforcement rings is not so suitable to resist the specified loadings in transportation.Secondly, to solve the problems, a new reinforcement structure is proposed. Strength and stability analysis for the whole tank shows that all the strength and stability requirements are satisfied with the new reinforcement structure. In addition, compared with the old reinforcement ring, the new reinforcement structure consumes less material and so the whole weight of the tanker is decreased.Thirdly, the fluid computation software FLUENT was used to simulate the liquid sloshing in a liquefied-gas tank with stress on the influence of the number and size of anti-wave plates on the sloshing. Results show that anti-wave plates can significantly decrease the maximum Impact force on the tank by the sloshed medium. Although increasing the number of the anti-wave plates cannot decrease the maximum Impact force remarkably, but it can smooth the sloshing and, thus, stabilize the moving of the tank. If keeping in a certain range, middle spacing of the anti-wave plate does not affect the sloshing and, therefore, the weight of the anti-wave plate can be minimized to save materials and increase the load-carry capacity of the tank.