Research On The Anti-explosion Protection Technology Of The Gas Pipeline Into The Comprehensive Pipeline Gallery

According to the requirements of Ministry of Housing and Urban-Rural Development of the People's Republic of China(MOHURD),it is necessary to incorporate gas pipelines into the utility tunnels.So that we must consider the explosion problem caused by the leaking of the gas.In order to explore the anti-explosion and protective technology,we need study the regular of vapor cloud explosion in the gas tank.This paper mainly used the method of numerical simulation to simulate the process of vapor cloud explosion in the gas tank,discussed the distribution law of the overpressure wave and the influence of the explosion on the surrounding in the gas tank.The following results have been achieved:1.By using ANSYS/FLUENT,we studied the degree of damage to the body and buildings caused by the overpressure wave which gone through the vent and the feeding port if occurring the most powerful explosion in the overflowing gas tank without pressure-relief vent and ignoring the superimposed effect of the overpressure wave.It is suggested that some industrial plants and high-rise buildings should not be built within 37.5 meters of feeding port and 20 meters of the vent.2.By using ANSYS/FLUENT,we studied that setting the pressure-relief vent inside the gas tank can effectively reduce the damage caused by the explosion,the effect of pressure relief will be better if the pressure-relief vent is below the feeding port and the vent.What's more,when the width of the pressure-relief vent is the same as the vent or the feeding port,the length of the pressure-relief vent is longer,the effect of pressure relief is better.When the ratio of the length of the pressure-relief vent and the feeding port or the vent is between 0.6 and 0.75,the efficiency and the effect of the pressure-relief is relatively well.3.By using ANSYS/AUTODYN,we researched that the explosion in the gas tank will have a certain impact on the subway tunnel just below the gas tank.The larger the distance of the gas tank and the subway tunnel,the smaller the impact;The softer the surrounding soil,the more difficult spreading the overpressure wave.In the condition of the specific sand in this paper,the advised vertical interval between the gas tank and the subway tunnel is not less than 7.2 meters.4.An optical cable temperature measurement system with sensitization protection function applied in a gas tank is proposed.This system uses fiber optic cable as a sensor,the steel tube which wrapped the cable as a protective layer.The two ends of the steel tube are connected to the same water source.When a fire occurs,the monitoring system controls the flow of water in the steel pipe to continuously take away the heat circularly,and the purpose of protecting the optical cable is achieved.5.An explosion-proof utility tunnel for explosion venting through the underground rainwater storage tank is proposed.In this utility tunnel,the gas tank is adjacent to the rainwater tank and at the bottom of them are drains.If an explosion occurs in the gas tank,the shock wave will damage the pressure-relief plate.Then the pressure is discharged to the drains,and the rainwater in the rainwater tank will also enter into the gas compartment,finally achieving the effect of buffering energy release.