Reliability Study And Accident Analysis Of High Pressure Gas Pipeline Based On FTF Method

With the rapid development of China’s natural gas industry,the development of high pressure gas pipeline in China has already become more and more stronger.But natural gas is a kind of flammable,explosive,toxic and corrosive gas,so that the pressure of natural gas pipeline program has become a high-risk industry.If the pipeline leak,will cause different degrees and types of accidents.These disasters not only threaten the safety of people’s lives,pollute the natural environment,but also bring serious economic losses,affecting the harmonious development of society.Based on the above reasons,it is very significant to study the reliability and accident analysis of the high pressure natural gas pipeline.According to the real situation of engineering,the dangerous and harmful factors of the high pressure gas pipeline are identified by this paper,which provides the basis for reliability analysis.Then established the analysis method of reverse FTF by using the fuzzy grey correlation FTA and fuzzy model FMECA.Then using this method on the reliability analysis of high pressure pipe.The research shows that the malicious damage,safety equipment failure and natural disasters are most important factors,which cause the pipeline leakage.The reliability of the whole pipeline is about 91.42%,by the comprehensive evaluation model of pipeline system,the safety evaluation grade B0=3.336;By the CA study,the earthquake will cause the most serious consequences.Secondly using CFD numerical simulation to analyze the influence of the size of the leakage aperture and the wind speed on the gas diffusion.Under the condition of the same transmission pressure,pipe diameter and leakage time,with the increase of the leakage aperture,the danger zone and the jet height of the natural gas will increase;The larger the wind speed is,the larger the angle of the natural gas is,and the range of the concentration diffusion will increase and then decrease;Under the condition of vortex motion,the high wind speed does not accelerate the dilution of natural gas,on the contrary,the natural gas in the downwind direction of the rotation of the gathering,the diffusion area and concentration are increasing.In order to forecast the disaster consequences,this paper calculated the three kinds of disasters by using the thornton jet fire model,fireball fire model and TNT equivalent model The results show that the hazard range of the three kinds of disasters decreases gradually with the increase of the distance from the accident point,and finally tends to be stable.For the three kinds of accidents,the death radius are compared,we find that the fireball is the biggest,the fire is the second,and the steam cloud explosion is the smallest.The research and analysis results provide a reliable basis for the project safety measures,the selection of management tools and the preparation of emergency rescue plans.