| Long tube trailers have unique advantages in the mass transportation of industrial gases.Because they run through the main road in cities containing high pressure inflammable medium,once the media leak the explosion will cause immeasurable losses of life and property.In order to effectively reduce the risk of the gas cylinder explosion from a long tube trailer,the cylinder is required to install the safety relief device by domestic and international standards and regulations.Due to various complicated factors,the safety release device has the probability of blasting in advance.However,at present the provisions of the standards and regulations for the structure and parameters are not consistent,while the structure,the blasting and fatigue properties of various safety relief devices are different.In recent years,accidents of premature rupture of safety relief devices have occurred many times,and these fatigue in complex cases has not been paid more and more attention.Based on this,the blasting and fatigue experiments were carried out using the safety release devices with different structures,which provided the reference for the provisions of the standards and regulations and the structural design of the device.Experimental studies were performed to study the fatigue behavior of rupture discs with different operating conditions and fatigue damage,and offered the suggestion for the safe use of the devices.According to experimental results,two new safety relief device were presented.The specific contents are as follows:(1)The technical standard differences of the safety relief devices for long tube trailer gas cylinders were compared and analyzed.The similarities and differences of the product structure between the mainstream manufacturers were defined,which provided the basic data for further research.Based on the analysis of the dangerous conditions of long tube trailer,the potential safety hazard was presented.(2)The fatigue test platform used for long tube trailer cylinder safety relief device was was built to measure the fatigue property with various types of rupture discs,fusible plugs and combined discharge devices.(3)The blasting and fatigue performances of safety relief device under the general condition were studied.According to the experimental results,the failure location and failure modes of the fatigue damage tests and the static pressure tests were different.Because the edge position of rupture disc was the stress concentration area,the cumulative fatigue damage under alternating load caused the rupture disc failure.As the pressure ring fillet of rupture disc decreased,the edge stress intensity of rupture disc increased while its fatigue life decreased.According to the analysis of the blasting and fatigue experiments with various safety relief devices,the existing security problems and some suggestions were presented to improve the standards and regulations.(4)The effect of operating conditions on the fatigue performance of the safety relief device was studied.It was found that the rupture disk life decreased significantly as increasing the circulating pressure,and the fatigue life of rupture disk increased as reducing the rate of pressure change and growth duration of peak pressure.(5)The blasting and fatigue performances of rupture disk on the damage condition were studied.That crush damage had no obvious effect on the rupture disk blasting pressure,but decreased significantly the fatigue life of rupture discs.When the damage shape was more blunt or the damage degree was greater,the fatigue life decreased obviously.Scratch damage would make the fatigue life of rupture discs decreased significantly.(6)Based on the shortage of the safety relief devices for gas cylinder from a long tube trailer,two new safety relief devices were developed.Respectively,they were the fusible bursting disc device and dual-disc blasting pressure relief device.The shortages of the safety relief devices were improved and these safeties were enhanced. |
PDF Full Text Request