The Gas Pipe Network Analysis, The Risk Of Impact Of Land Use Planning

Medium pressure gas pipeline, high pressure gas pipeline and gas storage and distribution station have the characteristics of high pressure and large gas storage capacity, so the risk of them is higher than other facilities in city gas transmission and distribution network. When there are other pipelines or buildings around them, it may lead to a domino accident, and the impact and consequence of them are greater. These high-risk facilities of city gas transmission and distribution network were in suburbs formerly, but with the accelerating process of urbanization they are gradually surrounded by populous residential area and other buildings. Some of the buildings have small spacing with the high-risk facilities, which may lead to a significant security risk. And there is lack of related laws and specifications about the safe distance around the gas pipeline network in china. Therefore, it is particularly important to calculate the safe distance between the medium pressure gas pipeline, the high pressure gas pipeline and the gas storage and distribution station with the surrounding buildings. Against that background, this paper uses the risk-based assessment method for land use safety planning to analyze the accident consequence of fire and explosion of high-risk facilities from the perspective of individual risk and social risk, draw risk distribution and set a safe distance around the pipeline. The safety distance can be used as the basis of safety surveying and evaluating the buildings around the city gas transmission and distribution network, and also be used as security planning guidance for new buildings location around the city gas transmission and distribution network. To simplify the calculation process, this paper develops software of land use safety planning for the city gas pipeline network. It is easy to use and make pipeline owners or gas companies have a clear understanding of accident consequence. It can change the focus of security management from disposal after the accident to prevention before the accident.This paper includes the following contents.(1) Some basic knowledge about land use safety planning for city gas pipeline network is introduced. The knowledge includes the definition of land use safety planning, three common methods of land use safety planning used in abroad containing the safe distance method, based on accident consequence method and risk-based evaluation method, the advantages and disadvantages of these three methods, the definition of risk, individual risk and social risk, the definition of risk acceptance criteria and its current development status.(2) Establish principles of operational process of land use safety planning for city gas pipeline network are illustrated and established. All steps of the operational process are done in-depth study. These steps include the regional gridding, data investigation, hazard identification, determination of worst-case accident scenario, analysis of the accident frequency and failure consequence, calculation of individual risk and societal risk, formulation of individual risk acceptance criteria and social risk acceptance criteria, determination of safe distance around the city gas pipeline network.(3) In order to improve the efficiency and accuracy of studying land use safety planning for city gas pipeline network, software of land use safety planning for city gas pipeline network is developed by MathCAD 2001 professional software tool in the Chinese Windows environment.(4) Operational process of land use safety planning for city gas pipeline network is applied to certain region of a city gas pipeline network, and the accuracy and practicality of it are tested. The individual risk and social risk of the region are calculated by using the software of land use safety planning for city gas pipeline network. Then, the safe distance around the pipeline is set by referring to the risk acceptance criteria, and it provides important reference for further planning in the region.