The Software Development For The Safety Assessment Of The Hazard System In Petrochemical Industry

With the development of petrochemical industry, production tends to high-temperature and high-pressure and macro-scale operations, and the safety issue of production has become more and more important. Thus, safety assessment has the important strategic significance for safeguarding the safety of people's lives and possessions and improving the development of social economy smoothly. There are many disadvantages in the traditional safety assessment. Traditional safety assessment rests on qualitative assessment, whose cycle is too long and efficiency is very low. In addition, assessment results depend on personal experiences in a high degree, which couldn't show the truth of system safety statement. With the fast development of computer, it has already become a necessary condition that applies information processing technique to safety assessment, which incarnates modern safety management method adequately. Main work of this paper can be sum up as follows:(1) Based on the analyses of several typic safety assessment methods, a safety assessment application software, which is applied to petrochemical industry, fuel gas production and storage equipment, has been worked out according to Dow's fire and explosion index. This software is suitable for assessing the safety of technical process of storing, disposing and producing flammable and active materials.(2) The software could be used to assess the safety of 328 materials in different technical flows and conditions, such as methane, ethane, ethylene, acetaldehyde and so on. The following results can be obtained: fire & explosion index (FEI), hazard grade, damage factor, base MPPD, actual MPPD, MPDO and BI. When FEI exceeds 128, the software reduces the FEI automatically to acceptable level by some proper safety allowance.(3) According to TNT equivalence method, the safety assessment program of vapor cloud explosion has been developed. The radius of death, GBH, flesh wound and property loss could be calculated when different flammable gases, such as methane, ethane, ethylene, acetaldehyde and so on, leak out into the atmosphere and explode under some conditions. It has been discovered that the higher percent of explosible fuel gas in the leaked is, the more heat of combustion is, and the more quantity of fuel leaked into the atmosphere is, the larger damage radiuses is.(4) UI (user interface) is designed with Visual Basic 6.0, and database of some parameters, such as material factor, heat of combustion, flash point, boiling point, and NFPA classification, is built up with Access2000. The software is friendly and simple. Many useful functions, including DB (database) query, addition, deletion, update, are offered. Except for inputting parameters step by step, professional training is not need for operators to assess the safety of dangerous units under different conditions.(5) By comparing the assessment results with data in report, it is found that the maximum divagation is within 5%. It shows that the software can be used to assess the safety of dangerous system, and is worth of engineering application.