Study On The Emptying System Of Changqing Large-scale Natural Gas Treatment Plant

The commonly used safety measures of Changqing gas field natural gas station is venting.It can timely discharge the exhaust gas of the pipe network and handle the unqualified gas occoured at the switch of the station.Besides,it can discharge gases at emergency to ensure the normal and safe operation of equipments.However,the inevitable vent design does have some security flaws to a certain extend.Inappropriate design may cause significant security problems,like casualties,property damage,fire and explosion accidents,and etcs.To solve this problem,this paper focuses on the determination on the size of the vent.One is based on the total amount of processing plant,the other is based on the accident state.At the same time,stress analysis and stability calculation is also used in the study to verify the reliability of the system.Hydraulic and exciting force of venting line under three conditions are calculated,so does the static analysis on flare stack system under three conditions.The setting of clamp constraints is proposed and the stability of high pressure vent torch system is analyzed.Sugesstions of torch wall thickness under high pressure is proposed in order to ensure the safe operation of the system.Thus theoretical analysis and calculation method is provided for the similar problems in the near future.Overpressure discharge,discharge volume and channel area of safety valve are caculated professionaly according to deduction and software.Then valve diameter is calculate and valve selection is conducted.Then torch comparation has been done from the selection of the venting line,the design pressure of the venting system and the setting of torch tower and finally sonic torch confirmed to be the best choice.Compared with the conventional torch,the sonic torch flame features high stability,long service life,safety and reliablity.Torch height,tube diameter and the diameter of vent system is lower than that of the conventional torch since the vent gas has high pressure and high flow rate.As a consequence,investment is saved;and environmental pollution is reduced because of the full combustion.