Discussion on the law of LPG leakage at the hottes

Discussion on the law of leakage (liquefied petroleum gas)

through the analysis of major accidents of liquefied petroleum gas at home and abroad, the accidental release type is proposed, and the potential accidental release type is proposed in combination with the production and storage site investigation, so as to find out the law of liquefied petroleum gas leakage and establish the source mode of liquefied petroleum gas leakage

in modern industrial disasters, fires and explosions caused by the leakage of liquefied petroleum gas occur frequently. Such as the disastrous accident caused by water cutting, gas escaping and tempering in Xiaoliangshan liquefied balloon tank farm in Gaoqiao, Shanghai; The pipeline from the catalytic cracking unit in Louisiana to the tank farm was torn, resulting in the destruction of the unit and the tank farm. According to the statistics of the world "30-year review of major property losses in the petrochemical industry" from 1966 to 1998, among the 10 accidents that caused the largest losses, 3 were caused by the leakage of liquefied petroleum gas. The establishment of ACTC R & D center in the international industry will realize that the government and many national scientific research institutions (organizations) have carried out a lot of research work on LPG fire and explosion accidents, and a lot of research work has been carried out on LPG leakage and explosion accidents, and the research on LPG leakage and diffusion model is one of the research hotspots. The first step to study the leakage and diffusion model is to study the leakage law of LPG and model the LPG leakage accident. The leakage source mode should reflect the main accident forms and be suitable for the production and storage status of LPG in China. Through the analysis of major LPG accidents at home and abroad, we put forward the accident release type, and combined with the on-site investigation of production and storage, we put forward the potential accident release type, so as to find out the law of LPG leakage and establish the mode of LPG accident source

from the previous major accidents, the discharge form of liquefied gas accidents is very complex, which is affected by many factors such as storage conditions, equipment, materials, meteorological conditions and so on. Through the comprehensive analysis of nearly 100 major liquefied gas accidents at home and abroad, they can be summarized into the following types of release:

1 explosive pressure liquefied gas

including: explosion of pressure liquefied gas storage tanks, tank cars, etc

basic form: a large amount of liquefied gas 7 The experimental velocity volume is set to discharge instantly, which leads to a large amount of air entrainment due to flash evaporation, and then the temperature of the cloud cluster drops sharply due to the evaporation of "droplets", forming a cold cloud cluster

2 continuous pressure liquefaction

includes: leakage of liquid phase holes, pipes, valves, etc. of pressure liquefied gas storage tanks

basic form: the released pressure liquefied gas flashes rapidly, mixes with the air and forms a low-temperature smoke cloud

3 non explosive pressure liquefied gas

includes: gas phase hole of pressure liquefied gas storage tank, small diameter pipeline, valve and other discharge

basic form: produce gas jet, and the discharge speed changes with the pressure in the tank

4 low temperature liquefied gas liquid

includes: the discharge of the liquid hole, pipeline, valve, etc. of the frozen liquefied gas storage tank, and the roof collapse of the low temperature tank

basic form: forming cryogenic liquid pool

5 two phase jet

includes: pressure, otherwise the operation of the fixture may exceed the service limit of the stroke, causing damage to the equipment, leakage of liquefied gas pipeline, and equal hole discharge in the gas phase of pressure liquefied gas storage tank

basic form: a "fog" or foam flow that produces changes

through the comprehensive analysis of the investigation results of the current situation of liquefied gas storage in Sinopec's internal enterprises, the following types of potential accident relief types are summarized:

1 valve and flange leakage

seal failure, corrosion, misoperation, processing defects, external loads

medium: gas, pressure liquefied gas, low temperature liquefied gas

2 pipeline leakage

causes: joint cracking and falling off, corrosion, processing defects, external load

medium: gas, pressure liquefied gas, low temperature liquefied gas

3 tank leakage

causes: corrosion, accessory defects, local processing and material defects

medium: gas, pressure liquefied gas, low temperature liquefied gas

4 explosive storage tank discharge

causes: overtemperature, overpressure, processing and material defects, external loads

medium: pressure liquefied gas

5 tank roof collapse

causes: overtemperature, overpressure, processing and material defects, external loads

the process of equipment commissioning and customer certification and evaluation is also long

medium: low temperature liquefied gas