Development Of Risk Pre-Assessment Technology For Process Industries

The prevention for serious accident during the processing, transportation and storage of hazardous substances has become focus problem and risk assessment is one of the most important prevention measures. Risk pre-assessment as the main branch of risk assessment plays a very important role in the program lifecycle.This paper develops a new risk pre-assessment technology based on HAZOP method;the major work and conclusions are as follows.(1) Bayed on the analyses on characteristics and requirements of pre-risk assessment in process industry, the adaptability of HAZOP to risk pre-assessment was confirmed.(2) The factors influencing the effectiveness and efficiency of HAZOP were revealed by eases investigation, and the critical path to save time of HAZOP was ascertained through CPM networking.(3) The procedure of risk pre-assessment technology and its required database were designed. A computer-aid ananlysis tool TFAHAZOP (Tool for Flow Automating HAZOP) was developed with Visual C++ 6.0, which is suitable for line-process flows and signal flows, and gives semi-quantitive results.(4) A knowledge base was set up including models of general knowledge object, special knowledge object, HAZOP object and accident case object, and the collection, analyses, processing and input of instance data.(5) The software's user interface is friendly and simple. Many useful functions, including database query, addition, deletion and updating are offered. Operators can obtain the results of risk pre-assessment on various conditions by automating HAZOP study function only by inputting parameters of a plant step by step according to instructions.(6) Practice of an actual program indicates that the new risk pre-assessment technique can supply more comprehensive results of equipment units and establish a closed relation between two conjoint equipment units compared with the conventional HAZOP method. This new pre-risk assessment technique can be used for risk pre-assessment in process industry.The new ideas presented in this paper are as follows.Firstly, by designing arithmetic of deviation propagation, the problem was solved that the conventional computer aided HAZOP method can not deliver the deviation inside of flows.Secondly, by constructing three signal equipment units, "controller", "sensor", "signal-line", the automating HAZOP analysis of signal flows was implemented.