Showing 3 results for Software
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.
Towhid Delshad, Farhad Shahraki, Mohammad Reza Sardashti Birjandi, Bahareh Bidar,
Volume 15, Issue 4 (12-2025)
Abstract
Introduction: Industrial units, such as oil refineries, face significant hazards due to the release of toxic and flammable gases. Hydrogen sulfide (H₂S), due to its high toxicity and environmental impact, is among the most dangerous pollutants. This study aimed to model and assess the consequences of H₂S release in the Sulfur Recovery Unit (SRU) of Abadan Refinery using PHAST software to support safety planning and risk reduction strategies.
Material and Methods: Consequence modeling was conducted using PHAST version 8.4. Process data, including temperature, pressure, flow rate, and feed composition, along with meteorological conditions (average temperature, relative humidity, and wind speed based on Pasquill stability classification), were used to define probable scenarios. Scenarios included partial pipeline rupture, variable leak flow, short pipe release, and catastrophic reactor tank rupture. Key damage criteria, including thermal radiation threshold, explosion overpressure, and toxic dose, were used to determine hazard zones.
Results: Thermal radiation up to 71.027 kW/m² can cause instant death within a 70-meter radius, while overpressure exceeding 0.206 bar can destroy equipment and structures up to 35 meters in summer conditions. The H₂S cloud can spread up to 120 meters downwind, causing immediate fatalities among exposed personnel. These findings identify high-risk zones in and around the SRU, emphasizing the need to relocate shelters, install gas monitoring systems, and provide protective equipment. Results are limited to the defined scenarios and PHAST assumptions.
Conclusion: Due to the lack of risk assessment studies in early phases and during operation, identifying safe points and high-risk zones, along with prioritizing risk reduction, is essential to ensure workplace and public safety. Comprehensive risk assessment, including probability analysis (using software such as SAFETI) and application of advanced models (CFD and AI-based methods), is recommended for future research.
