Saber Moradi Hanifi, Leila Omidi, Gholamreza Moradi,
Volume 9, Issue 1 (4-2019)
Abstract
Introduction: Fire and explosion are the most common consequences of natural gas pipeline accidents. The results of previous studies showed a higher rate of accidents in natural gas transmission lines. Given that a large number of people living in the vicinity of natural gas pipelines with a higher severity of related accidents. The aim of current study was to estimate risks using the method of quantitative calculation of risk and simulation of natural gas pipeline leakage using areal locations of hazardous atmospheres (ALOHA) in natural gas power generation.
Material and Methods: The method of quantitative calculation of risk was used to identify and prioritize risks. The simulation of the consequences of natural gas pipeline leakage was done by ALOHA software. Calculations of individual and social risks were performed based on statistical data obtained from the literature.
Results: The most serious effect of natural gas pipeline leakage was heat radiation effect of jet flame. Considering three leakage apertures in the natural gas pipeline 80, 130, and 300 mm, individual risks for each leakage aperture were 0.073, 0.114, and 0.569 and the number of deaths was 115, 400, and 3386, respectively. Increases in the leak aperture can lead to an increase in the number of deaths and decrease in the cumulative rate of accidents.
Conclusion: The most serious consequence of natural gas pipeline leakage was heat radiation effect of jet flame. The individual risk and social risk are beyond the acceptable risks range.
Seyed Mahdi Mousavi, Ali Karimi, Seyed Abolfazl Zakeriyan, Mehrdad Mehravar,
Volume 12, Issue 1 (3-2022)
Abstract
Introduction: Permit-to-work system (PTW) system is a documented system to control the activities with inherent risks and probability of accident occurrence. To inform the performance and efficiency of a system, it must be periodically monitored and evaluated, and the permit to work system is no exception of this principle. The aim of the present study was to design and develop software for evaluating the performance of the PTW system.
Material and Methods: This study included two main stages. At the first stage, based on the literature review and interview to the academic and industrial experts, the PTW questionnaire for evaluating the performance was created. The second stage involved the design and implementation of an initial version of a software and the investigation of its usability. Designing the software was performed using system development life cycle (SDLC). The usability of this software was evaluated by Think -Aloud method. Finally, the users’ satisfaction was measured using the Questionnaire for User Interface Satisfaction (QUIS) questionnaire.
Results: Based on the results of the QUIS questionnaire, the overall satisfaction of the designed software was 7.71 in a nine-point scale. The scores of the software performance, display and user interface features, software terminology and information, learning, and overall system capabilities were obtained as 7.58, 7.37, 7.75, 8.11, and 7.74, respectively. Also, the outputs of the excel and SPSS software were in accordance with those of designed software, which show the reliability of the outputs of the designed software.
Conclusion: The designed software facilitate the proper and systematic analysis and it is flexible to evaluate the PTW system and represent types of reports in predefined structures that can be a useful tool in the process industries such as oil and petrochemical refineries and other similar industries.
