scholarly journals QRA-Grid: Quantitative Risk Analysis and Grid-based Pre-warning Model for Urban Natural Gas Pipeline

2019 ◽  
Vol 8 (3) ◽  
pp. 122 ◽  
Author(s):  
Shuang Li ◽  
Chengqi Cheng ◽  
Guoliang Pu

With the increasing use and complexity of urban natural gas pipelines, the occurrence of accidents owing to leakage, fire, explosion, etc., has increased. Based on Quantitative Risk Analysis (QRA) models and Geographic Information System (GIS) technology, we put forward a quantitative risk simulation model for urban natural gas pipeline, combining with a multi-level grid-based pre-warning model. We develop a simulation and pre-warning model named QRA-Grid, conducting fire and explosion risk assessment, presenting the risk by using a grid map. Experiments show that by using the proposed method, we can develop a fire and explosion accident pre-warning model for gas pipelines, and effectively predict areas in which accidents will happen. As a result, we can make a focused and forceful policy in areas which have some potential defects in advance, and even carry out urban planning once more, rebuilding it to prevent the risk.

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Xian Shan ◽  
Kang Liu ◽  
Pei-Liang Sun

Pipeline is the major mode of natural gas transportation. Leakage of natural gas pipelines may cause explosions and fires, resulting in casualties, environmental damage, and material loss. Efficient risk analysis is of great significance for preventing and mitigating such potential accidents. The objective of this study is to present a practical risk assessment method based on Bow-tie model and Bayesian network for risk analysis of natural gas pipeline leakage. Firstly, identify the potential risk factors and consequences of the failure. Then construct the Bow-tie model, use the quantitative analysis of Bayesian network to find the weak links in the system, and make a prediction of the control measures to reduce the rate of the accident. In order to deal with the uncertainty existing in the determination of the probability of basic events, fuzzy logic method is used. Results of a case study show that the most likely causes of natural gas pipeline leakage occurrence are parties ignore signage, implicit signage, overload, and design defect of auxiliaries. Once the leakage occurs, it is most likely to result in fire and explosion. Corresponding measures taken on time will reduce the disaster degree of accidents to the least extent.


Author(s):  
Y.-D. Jo ◽  
K.-S. Park ◽  
H.-S. Kim ◽  
J.-J. Kim ◽  
J.-Y. Kim ◽  
...  

Author(s):  
Chunyong Huo ◽  
Chuanjing Zhuang ◽  
Minxu Lu ◽  
Helin Li ◽  
Guoxing Li

Quantitative risk analysis was carried out on a proposed natural gas pipeline based on preliminary data using the methods and models implemented in the PIRAMID™ software program. The high-risk areas were identified and the main causes of risk were analyzed. Measures to lower the calculated risk levels were developed, which will be taken into consideration in the design and construction of the pipeline.


Gases ◽  
2021 ◽  
Vol 1 (4) ◽  
pp. 156-179
Author(s):  
Abubakar Jibrin Abbas ◽  
Hossein Hassani ◽  
Martin Burby ◽  
Idoko Job John

As an alternative to the construction of new infrastructure, repurposing existing natural gas pipelines for hydrogen transportation has been identified as a low-cost strategy for substituting natural gas with hydrogen in the wake of the energy transition. In line with that, a 342 km, 36″ natural gas pipeline was used in this study to simulate some technical implications of delivering the same amount of energy with different blends of natural gas and hydrogen, and with 100% hydrogen. Preliminary findings from the study confirmed that a three-fold increase in volumetric flow rate would be required of hydrogen to deliver an equivalent amount of energy as natural gas. The effects of flowing hydrogen at this rate in an existing natural gas pipeline on two flow parameters (the compressibility factor and the velocity gradient) which are crucial to the safety of the pipeline were investigated. The compressibility factor behaviour revealed the presence of a wide range of values as the proportions of hydrogen and natural gas in the blends changed, signifying disparate flow behaviours and consequent varying flow challenges. The velocity profiles showed that hydrogen can be transported in natural gas pipelines via blending with natural gas by up to 40% of hydrogen in the blend without exceeding the erosional velocity limits of the pipeline. However, when the proportion of hydrogen reached 60%, the erosional velocity limit was reached at 290 km, so that beyond this distance, the pipeline would be subject to internal erosion. The use of compressor stations was shown to be effective in remedying this challenge. This study provides more insights into the volumetric and safety considerations of adopting existing natural gas pipelines for the transportation of hydrogen and blends of hydrogen and natural gas.


Author(s):  
Jung-Suk Lee ◽  
Jang-Bog Ju ◽  
Jae-il Jang ◽  
Dongil Kwon ◽  
Woo-sik Kim

There are buried natural gas pipelines of which total length amounts to about 2.1×106m in Korea, and it is very important issue to evaluate FFS (Fitness-for-service) when a crack-like flaw was found in operating pipelines. But, the research about this had not yet been performed in Korea. So, this study constructed a FFS code appropriate to Korean natural gas pipeline through comparing and analyzing API 579 and BS 7910 that are lately. In addition, we developed the user-friendly software based on FFS code, so that field service workers who have little idea about fracture mechanics can use easily. The best merit of this code is that it is possible to evaluate FFS for welding HAZ in Korea natural gas pipeline.


2020 ◽  
Vol 7 (2) ◽  
pp. 17-26
Author(s):  
Pedro Quintela ◽  
Jean Carlos Pérez Parra ◽  
Lelly Useche Castro ◽  
Miguel Lapo Palacios

The transient flow analysis is fundamental to the simulation of natural gas process, in order to adjust the system to real operative conditions and to obtain the highest level of efficiency, compliance and reliability. The simulation of natural gas pipelines and networks requires mathematical models that describe flow properties. Some models that have been developed year after year based on the laws of fluid mechanics that govern this process, interpreted as a system of equations difficult to solve. This investigation describes the fully implicit finite volume method for natural gas pipeline flow calculation under isothermal conditions and transient regime. The simplification, discretization scheme and implementation equations are approached throughout this paper. The model was subjected to two evaluations: sinusoidal variation of the mass flow and opening-closing valve at the outlet of the pipeline, it is compared with two models: fully implicit finite difference method and method of characteristics. This method proved to be efficient in the simulations of slow and fast transients, coinciding the flow oscillations with the natural frequency of natural gas pipeline.  


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