摘要
天然气管道长时间输送会在管壁产生积液和杂质,影响管道的正常运行,因此需要定期进行清管作业。针对清管作业接收筒易发生燃爆事故的问题,依据其工作流程,利用事件树方法对其燃爆事故的演化过程进行分析,并根据结果设计燃爆事故的模拟工况。通过FLACS软件分析了不同工况下筒内初始压力和风速对燃爆伤害范围的影响。结果表明：对于因泄压造成的燃爆事故,筒内超压最大值约是初始压力的7. 5倍,当筒内初始压力超过0. 5 MPa时,燃爆产生的超压可能会导致筒体破裂,据此提出改进截止阀的安装位置或在放空阀处安装防回火保护装置的预防措施;对于因取出清管球操作失误而导致的燃爆事故,燃爆超温远大于人体承受温度,且风向对事故火势延伸有较大影响,在顺风环境下接收筒3 m内会对操作人员造成严重伤害,应在盲板处安装水喷淋装置,防止事故对人员的伤害。
The present paper is concerned about a study on bow to deal with the problem of fire and explosion accidents that are likely to take place in the receiving tube of the pigging operation based on the analysis of the evolutionary process of the accident-causing conditions. And, for the said purpose, we have first of all brought about the reasonable logical accident-leading conditions by using an event tree analysis （ETA） as to the gas-pipe walls of the natural gas pipeline that would like to accumulate the fluid-mixed impurities if they are working for long. As is well known, since the fluid like mixed impurities tend to affect the normal operation of the pipeline, it would be necessary to keep it cleaned on the regular terms. Nevertheless, there exist a lot of uncertainties in the cleaning operation spots, which may even lead to the fire and explosion accidents from time to time. The reasons for such accidents can be stated as follows. First of all, the receiving cylinder would like to meet fire source when the ventilation valve pressure is released, which would lead to the abrupt temperature rise. Secondly, in the process of turning off the blind plate, it is likely for the operational work to encounter fire due to its likely-done errors. In order to analyze the impact of the initial pressure and the wind speed on the range of the explosive damage under the different working conditions, it is necessary to build up a simulation model of the pigging receiver tube with a FLACS software, and then to reduce the liability of the accident incidence to the minimum extent in addition to taking reasonable preventive measures. Thus, it can be seen that our study has managed to reduce the maximal overpressure in the cylinder by about 7.5 times the initial pressure in the fire and explosion accidents by relieving pressure, for, when the initial pressure in the cylinder exceeds 0.5 MPa, it would be possible for the cylinder to get rupture, leading to the shockwave abruptly turning up to hurt the nearby operators. To change the situation, we suggest to change the location of the shut-off valve assemble or install anti-temperature protection device on the point of the emptying valve to prevent such accidents, for the explosion o- verheating can be far greater than the temperature that the human body can bear. Moreover, the wind direction can also have a great impact on the spread of the fire in such accidents, so that the fire subjects in a sphere of 3 m of the wind environment are likely to get hurt. Therefore, the operator has to be evacuated as soon as possible and the water spray should be installed in the blind plate to prevent from the spread of the accident.
作者
朱渊
杨强
左腾腾
郭子琛
安思颖
ZHU Yuan;YANG Qiang;ZUO Teng-teng;GUO Zi-chen;AN Si-ying(College of Mechanical and Electronic Engineering,China Uni-versity of Petroleum,Qingdao 266580,Shandong,China;Cen-tre for Offshore Engineering and Safety Technology,China Uni-versity of Petroleum,Qingdao 266580,Shandong,China)
出处
《安全与环境学报》
CAS
CSCD
北大核心
2018年第5期1762-1767,共6页
Journal of Safety and Environment
基金
国家重点研发计划(项目编号:2017YFC0804500)
中央高校基本科研业务费专项资金资助项目(18CX05010A)
工业和信息化部高技术船舶科研计划项目(工信部联装[2016]24号)
关键词
安全工程
清管作业
天然气
燃爆事故
数值模拟
超温超压
safety engineering
pigging operation
naturalgas
fire and explosion accidents
numericalsimulation
over-temperature and over-pressure
