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This post was last edited by safetydynamic on 2021-5-29 at 13:02. Globally, aside from the corporate standards set by various companies, there are three main standards regarding the analysis of the placement of fire and gas detectors. The first of these is ISA-TR 84.00.07, developed by the Instrumentation Society of America; it is the earliest standard established for this niche industry and has had the most significant impact. Work on this standard began in 2006, with the first version released in 2010. The second major standard is GB-T39173, issued by the Standardization Administration of China. Development of this standard started in 2017, it was released in October 2020, and its official implementation began in May 2021 – so it is still quite new. It is likely to gradually influence the standards used in domestic and international EPC projects. The third standard is BS-60080, which is governed by the British BSI standard; it was also published in October 2020, essentially at the same time as GBT39173. The full extent of the impact has not yet become apparent; it is likely to affect mainly the European region. Citing the provisions of ISA-TR 84.00.07, the Standard for Guidelines for Performance Evaluation of Fire and Gas Detection Systems issued by the Instrumentation Society of America, it is stated that the key to evaluating fire and gas detection systems is that the evaluation itself must employ accurate and traceable methods. This means that it is necessary to evaluate not only the hardware and software components of such safety systems, but also their underlying design. Based on such considerations, therefore, regardless of the choice of detector model and range, the number and placement of detectors, the setting of angles, as well as all aspects of the system’s hardware and software, designers must take into account the characteristics of the manufacturing process in their overall design. According to the HSE database OTO 93:002 in the UK, the effectiveness of detectors arranged using traditional methods in practical applications is only around 40%. However, the designers do not have any standard to follow explicitly in their design work. As stated in the first paragraph of BP’s fire detection design standard BP30-85, no ** or international standard has yet established clear specifications for fires and gas leaks, as well as methods for designing detectors. Since the early 2000s, Royal Dutch Shell was the first company to use specialized analysis software for the strategic placement of detectors. To this day, many major petrochemical companies around the world – including Chevron and ExxonMobil in the United States, Shell and BP in Europe, Total in France, BASF in Germany, Kuwait’s KNPC and Saudi Aramco in the Middle East, as well as Petronas in Malaysia and PetroVietnam in Vietnam in Asia – routinely employ software simulations for the quantitative design of fire and gas detectors. Driven by the demands of contemporary times and system security, software-based computing methods have gradually been adopted in the petrochemical industry. As an important component for quantitatively assessing the safety and integrity of fire and gas detection systems, these methods ensure that the overall evaluations of such systems are based on reliable data. The software uses quantitative methods to calculate the coverage rate of detectors for flames, flammable gases, toxic gases, etc., in order to verify and optimize the detector placement design. It is an effective means of preventing dangerous accidents from occurring and controlling the severity of their consequences. Its advantages are: ——compared to qualitative analysis, it can provide quantitative coverage rates and layout plans, thereby avoiding the impact of subjective factors on the effectiveness of fire detection. ——Although the qualitative analysis process is not simple, its results are accurate, and this method can be applied after qualitative analysis to optimize the analytical conclusions. ——Evaluate using the results of 3D design, and provide a visual analysis process and results. 1) The development of fire detection layout technology began as early as the late 20th century. Shell commissioned the third-party software company Gexcon to develop software for layout analysis. In its initial version, this software conducted only geometric analyses, carrying out calculations based on assumed detector coverage parameters; the algorithm relied solely on two-dimensional graphics, had a simple logic, and produced relatively rough results (as shown in the diagram). During that period, some oil companies began using DNV’s PHAST software for preliminary analysis of gas dispersion, manually arranging detectors based on the analysis results. The algorithm behind PHAST software, which is based on a Gaussian model, does not take into account the three-dimensional structure of the facility; as a result, its accuracy is too low for practical use, and it can only be employed for rough estimates over distances of a few dozen kilometers. Between 2003 and 2008, some companies in Europe, such as Hazras in the UK, began to recognize these issues and started using CFD algorithms for fluid dynamics to calculate the dispersion of gas clouds. However, computer capabilities and the algorithms themselves were still relatively underdeveloped at that time; significant amounts of human, financial, and material resources were required for such calculations, and post-processing also had to be carried out manually. There are also some manufacturing companies, such as the British company Micropack, which is a manufacturer of flame detectors. They began working with BP in 2003 and developed software designed to assess the coverage of flame detectors. Initially, this software was used only for evaluating flame detectors, but it was later adapted to be used for evaluating gas detectors as well; however, these software programs still rely on two-dimensional systems for their calculations. In 2006, the ISA – American Society of Instrument and Control Engineers began inviting various professional companies to collaborate on the development of ISA-TR 84.00.07, which is a guide for evaluating the performance of fire and gas detection systems. Version B of this document was released in 2008, while the final version was published in 2010. The original intention of this guide is to incorporate the performance evaluation of fire and gas detection systems into the evaluation methodology framework for functional safety systems. In accordance with these guidelines, the methods to be used and the applicable scenarios for site selection techniques are clearly specified. As the author of this guide, the software developed by the American company Kene*s has been used in numerous projects by Chevron and ExxonMobil. Initially, this software was based on 2D technologies (such as diagrams), but it gradually acquired the capability to perform 3D modeling calculations. Since 2010, as placement technology has matured, this type of technology has begun to be applied in projects in the Middle East and Asia. In Asia, Petronas was the first to adopt it; its Function Safety Research Group at Petronas University received instructions from the company’s headquarters in 2007 to work together with the British company MicroPack on developing analysis software owned by Petronas (such as the visualization tools used). However, since these algorithms were based on geometric models, a large number of detectors had to be used in actual projects, which caused dissatisfaction among the operating entities. Currently, Petronas is investing more resources within its universities to develop software capable of performing scenario-based analysis. By 2018, Shell’s site selection software mainly continued to rely on collaboration with the software company Gexcon to incorporate elements of CFD simulation technology into it; however, the subsequent analysis was still carried out manually. Petronas, on the other hand, used software developed by itself ； A company in the UK, Micropack, has upgraded its analysis software to use three-dimensional models for calculations, but it has not adopted CFD calculations either ； There are two specialized companies in the United States. One is Kene’s, which has a long history; it can now perform three-dimensional geometric analysis, with its parameters derived from calculations using Phast software, but it does not utilize CFD technology. The other company is InsightNumeric, founded in 2013; it has developed two software programs: Detect3D (as shown in the diagram) and Influx (also as shown in the diagram). Detect3D is a software based on three-dimensional geometric calculations and corresponds to spatial analysis, while Influx is a CFD-based software used for scenario analysis. These are two separate software programs. Influx is the CFD simulation software offered by insight Numeric; it has been optimized for simulating gas diffusion, enabling the simulation of gas diffusion under various scenarios. Additionally, the software takes into account factors such as the location of leakage points, the probability of leaks occurring, and the direction of gas release, and it also includes a CFD meshing function. inFlux proposes a risk-based method for detector placement, which is relatively innovative; it relies on calculating the probability distribution of gas concentration levels after numerous diffusion clouds overlap. However, it also points out that the detector placements determined through spatial analysis differ significantly from those derived from scenario analysis, creating a technical contradiction. The domestic software company Safety Dynamic, Shanghai Hehan Technology Co., Ltd. (www.safetydynamic.com), was established in 2012. The CFD module used in the scenario calculation of its GCV software is implemented through interfaces with mainstream computing software such as Fluent/CFX/OpenFoam/Flacs. GCV is currently the only fire and gas placement software on the market that can perform both spatial-based calculations and scenario-based calculations. Unlike the development path of other site selection evaluation software, traditional such software evolved from two-dimensional to three-dimensional approaches, with an gradual shift from geometric (spatial) analysis to scenario-based analysis and calculation. GCV, on the other hand, was developed directly from three-dimensional scenario-based analysis starting in 2012, before gradually expanding to include spatial analysis as well as comprehensive analysis methods. Over approximately 6 years of development since 2012, GCV matured and eventually surpassed the performance of most similar Western software used for fire and gas site selection evaluation. For the Nippon Halong Center project built by Petronas in 2017, different software solutions from three companies (Kene’s, InsightNumeric, and SafetyDynamic Integrated Technologies) were used to analyze the effectiveness of fire and gas site selection; ultimately, it was the reports generated by GCV that served as the basis for modifying the entire center platform. The project was recognized for its success, and a white paper detailing its successful implementation was published. Due to limitations in company size, at present Hehan Technology mainly builds its influence in the domestic market and those in Southeast Asia. The concept for GCV originated in 2010 with conceptual design work, and market research and module design began in 2011. It was developed as a result of an accident that occurred at the propylene separation tower at Formosa Plastics’ Taichung refinery in Taiwan. Unhappy with the placement results determined by Kene’s using spatial analysis methods, Formosa Plastics requested that CFD technology be used to calculate the appropriate locations for the detectors, and thus the GCV software was created to meet their requirements. Unlike the development trends of other site-planning software, Hehan Technology is committed to transforming such software from pure design tools into real-time systems. In particular, for gas tracking systems, the models developed incorporate the results of site-planning analyses; servers located in the cloud collect data from sensors on-site as well as information on wind speed and direction. The CFD calculations provide the necessary framework for these systems, and the engine can use the readings from gas sensors along with wind speed and direction data to determine the location of leakage areas. At the same time, it is possible to continuously verify and adjust the detector position, which may also be a direction for future development. Shanghai Hehan Technology Co., Ltd. www.safetydynamic.com