The Analysis On Anti-explosion Performance Of Cargo Hold Structure Of CNG Carrier

Compressed natural gas carrier is mainly used to transport natural gas.Natural gas is stored in the form of high-pressure cylinders,the carrier has a complex cargo system,which pipeline system and the main container is the main system of natural gas storage,loading and unloading.Due to the vibration,bearing stress and the cause of the longitudinal bending,the gas leakage of the pipeline valve,the failure of the gas cylinder and the poor sealing in the cylinder manufacturing process lead to gas leakage.Once the leakage of gas encountered open flame,electrostatic and other adverse factors will occur gas explosion.Explosion will pose a serious threat to the ship structure.In order to ensure the safety of the ship and improve the vitality of ship,this paper studied the anti explosion performance of compressed natural gas transport ship in gas explosion loads.The main research work is as follows:(1)Based on the study of gas explosion shock wave theory,the nonlinear transient dynamic calculation software MSC.Dytran was used to simulate the propagation of gas explosion shock waves in the air.The empirical formula given by Henrych was used to compare the finite element simulation results,The results are of sufficient computational accuracy.It is proved that it is feasible to use MSC.Dytran software to simulate the gas explosion shock wave propagation in the air.At the same time,the influence of the density coefficient of grid and different methods on the peak pressure of shock wave was studied.(2)By analyzing the arrangement of pipeline,the failure mode of gas cylinder and the risk source of gas leakage inside and outside the cabin,the gas leakage and the location of explosion source are determined.The general coupled method was used to simulate the antiknock performance of the cargo hold structure under the shock wave load of the gas leakage explosion of the compressed natural gas carrier.(3)By analyzing the dynamic response of cargo hold structure under explosion load,three reinforcement schemes were determined.The deformation,stress and structural deformation energy absorption of the cargo structure under three different strengthening modes are analyzed for the most unfavorable location of the blast source.By comparing the three reinforcement schemes with the original structure,the effects of different strengthening methods on the anti-blast performance of the structure were determined.