ANALYSIS OF SAFETY OF A CNG CYLINDER UNDER IMPACT

Abstract

The human mind has been working towards making the life of mankind more productive and easier. From the invention of wheels to bullet trains, man has found his curiosity to be the driving force behind so many inventions. Man has been using oil as a fuel for a long time to travel. However, not only the oil resources are depleting fast but using oil as a fuel has hazardous effects on the environment. Compared to oil, natural gas is not only abundant but also has better results than oil when it comes to environmental protection. Over the years, inflation in Pakistan and in general, the world, has forced the owners of automotive industries and vehicle owners to look for alternate options. One such option is Compressed Natural Gas (CNG) [6]. Compressed below one percent of its total volume, this natural gas provides many benefits as a fuel compared to oil. However, with its many benefits, the use of CNG has resulted in some issues just as any with other technology. Like many other countries, Pakistan introduced CNG because of lower costs, lesser emissions, and better availability at the time. However, over the years Pakistan became one of the largest countries to use CNG as a fuel in vehicles. Pakistan had more than three million vehicles running on CNG at one time The number has reduced somewhat due to the lack of availability of CNG over the years and lack of good Government Policies. Like any other technology, Natural gas Vehicles (NGVs) running on CNG have had some issues. One major issue among them is the failure of the CNG cylinder in the case of an accident. It has been observed that under the impact, the CNG cylinder results in an explosion, or the cylinder body may be rendered unusable in the future. Studies show that there has been an increase in accidents involving CNG cylinder explosions [6]. There have been many accidents related to Natural Gas Vehicles in Pakistan. A lot of these accidents have involved an explosion. These explosions could have been caused by leakage from the fittings attached to the CNG cylinder or the CNG cylinder itself [7]. iv Specifically, in Pakistan, there have been a large number of accidents related to NGVs in the past years where a CNG cylinder exploded or was rendered unusable for the future. This generates a requirement for reconsideration of the cylinder‟s design, material, method of formation, location, etc. Hence, now is the time to make sure that the CNG vehicles operate safely and that no threats are posed by the CNG cylinder. In this study, we worked on the safety of a traditional all-steel cylinder under the impact on different locations of a passenger car. The project inspects the cause of such cylinder explosions and provides suggestions on how to improve the design to increase the safety of the passengers. Each location was given a different impact situation. We also studied if the cylinder body would be able to withstand the impact to the point that it would be rendered reusable after the first impact or would the cylinder body be damaged to the point of no further usability.