Study On The Reliability Of Water Spray Fire Extinguishing System In Petrochemical Plant Area

Based on the fire characteristics of petrochemical enterprise in production plant area, fire-fighting is focused on fire prevention, aiding fire firstly, protection of fire fighting, protecting and cooling equipment, etc. But just setting fire hydrant and fire water cannon as fire-fighting facilities in production plant area is not enough. Spray extinguishing system is an automatic fire extinguishing system that is developed by the automatic sprinkler system. System’s fire fighting function mainly displays in surface cooling, suffocation, emulsification. Cooling and suffocation is difference. For the water-insoluble liquid hydrocarbon fire, emulsification has special effect to put out the fire. Based on the function of water spray extinguishing system, the system can be applied to electrical fire, combustible liquid fire, solid surface fire, etc. The system can also be used for class A or B flammable liquids and flammable gas production equipment, pipeline cooling and protection. The system is widely used on the petrochemical enterprise area fire control system.Spray extinguishing system’s research about petrochemical enterprise production area mainly concentrated in system’s design and application. The reliability of the area of water spray extinguishing system in a petrochemical plant research is less. This paper analyzes the petrochemical enterprise production area water spray extinguishing system function reliability. Analysis system of fire fighting water supply, fire water pump station, fire water supply pipe network, deluge valve chamber, the deluge valve group and the main fire pump start alarm linkage controlling system, confimming factors that influence the reliability of the water mist sprayer. Using fault tree-bayesian network model, a fuzzy fault tree model, L-R type fuzzy fault tree model, calculate quantificationally system reliability interval distribution and fuzzy reliability of single value respectively. Finally using bayesian network belief propagation algorithm, the weighted structure important degree respectively, calculate quantificationally model of important degree, and establish a petrochemical plant area water spray extinguishing system reliability research model.Selecting some petrochemical enterprise of tianjin ethylene plant area water spray extinguishing system as the research case, to analyze system function reliability. Proposed system fire pump station’s main fire pump group should adopt hybrid drive, block deluge valve chamber wall wear tube, the deluge valve chamber wall wear tube for containment, adopt explosion-proof solenoid valve in the deluge alarm valve group.Using fault tree-bayesian networks evaluation method’s credential operation method, can obtain the system failure times is about 8.5- 11.6 times evrey year, and the system reliability of interal is (0.9987,09990). Using L-R type fuzzy fault tree evaluation method, can obtain the system failure probability is about 10 times evrey year, and the system reliability is 0.9988. Analysizing the business ethylene plant water spray extinguishing system’s failure basic event to the important degree of reliability, can get that the rain god alarm valve group which is deluge valve, solenoid valve, signal butterfly valve and so on, is the he key parts of influencing the system reliability. Advising businesses focus on strengthening maintenance and management of the deluge valve group.The assessment mode of analysizing water spray extinguishing system functional composition and function reliability of the process, for the reliable operation of petrochemical plant area water spray fire extinguishing system, realizing the system availability, can provide scientific theory research methods.