Study On Thermal Response And Safety Evaluation Of Long Tube Trailer Cylinders Exposed To Fire Environment

Tire fire accidents may be occurred for long tube trailers during transportation.The action of the safety relief device may be delayed due to insufficient heat input.The gas cylinder may blast before the action of the safety relief device due to the degraded of the mechanical properties of the cylinder material.There is a huge potential safety hazard for gas cylinders.Based on these backgrounds,the experimental and numerical studies for a large capacity steel seamless gas cylinder under local fire environment was carried out.The thermal response of the cylinder and the gas medium exposed to tire fire environment was studied,and the safety of the cylinder was also evaluated.The main contents and conclusions are listed as following:(1)The experimental and numerical studies of thermal response laws for a large capacity steel seamless cylinder exposed to local fire environment was carried out,the thermal response laws of the gas cylinder and gas medium was obtained and the rationality of the numerical simulation method was also proved.The results indicate that the simulation results are in good agreement with the experimental results,and the numerical model established can simulate the fire experiment accurately.(2)The numerical simulation of thermal response laws for a long tube trailer cylinder exposed to tire fire environment was done.The effects of medium types and the number of ablaze tires on thermal response laws of the gas cylinder was also researched.The results indicate that the high-temperature zone of the gas cylinder is located near the tire at the start of tire fire,then the heat will transfer to the low-temperature part of the gas cylinder and gas medium through heat convection and heat conduction.The temperature of the gas cylinder and gas will increase continuously.The types of filling mediums have little effect on the thermal response laws of the gas cylinder and gas medium,and the more numbers of ablaze tires is,the faster thermal response of the gas cylinder and gas medium will be.(3)The blasting pressure of the gas cylinder was calculated based on the limit load method,and the safety assessment of the gas cylinder was also done.The results indicated that the action of the safety relief device happened before the blast of the gas cylinder,indicating that the gas cylinder is safe under tire fire environment.