Establishment And Application Of The Index System For Leak Detection And Repair Assessment In The Petrochemical Industry

In the petrochemical and chemical plant production processes,fugitive emissions of volatile organic compounds(VOCs)are regularly released due to imperfect sealing of the valve parts such as flanges,valves and connectors.It not only causes the air pollution,but also causes the loss of the pipeline VOCs material.The unorganized leaks of these equipment components are usually not easy to find,but can be identified using instrumental testing.Leak Detection and Repair(LDAR)is a common technology used at home and abroad to control unorganized emission of VOCs in petrochemical industry.It is the use of testing equipment for VOCs emission and leakage detection device components,and within a certain period of time to seal leaks over the standard repair,thereby directly reducing VOCs emissions.Since 2014,China has vigorously promoted leak detection and repair technologies in the petrochemical industry.The technology of LDAR has been rapidly developed in China.At present,many petrochemical companies have carried out leak detection and repair work in a number of rounds.However,at present,the technical specifications and standards of LDAR in various parts of China have not yet been completely unified.There are many problems in the some aspects,such as on-site detection and repair,operation and management of LDAR.Therefore,in order to find out the effect of LDAR and regulate the healthy development of LDAR,it is imperative to carry out the assessment of the entire life cycle of LDAR.In this paper,the research object is construction of leak detection and repair evaluation indicator system in petrochemical industry.Based on the LDAR theory,combined with the LDAR evaluation of 60 sets of petrochemical chemical plants in Tianjin in 2015,the research on the index system of LDAR evaluation is carried out.Considering the key nodes in the whole life cycle of leak detection and remediation,24 indexes of 4 levels including LDAR project establishment,on-site detection,leak repair,routine operation and management are selected in the design of evaluation index.The method of analytic hierarchy process and fuzzy comprehensive evaluation is used to construct the evaluation index system of LDAR.The analytic hierarchy process(AHP)is used to establish the weight of the index of leakage detection and repair,and the comprehensive evaluation of leak detection and restoration index is made by fuzzy comprehensive evaluation model.The combination of the two methods improves the effectiveness and scientificness of the assessment method model.Finally,the constructed evaluation index system of LDAR is applied to the LDAR evaluation of A and B petrochemical enterprises.The evaluation results of the indicator system are consistent with the actual assessment results,this shows that the LDAR evaluation index system has a good value for promotion and employ.