(49b) Addressing the Unique Challenges of Hydrogen Gas Detection and Its Way Forward in 3D Fire & Gas Mapping

Fixed Fire and Gas Detection Systems play a crucial role in enhancing safety at process plants, mitigating risks to personnel, the environment, and the facility. These systems are vital for detecting leaks, toxic or flammable gas build-ups, and the presence of fires, which could lead to hazardous situations. To optimize the placement of these detection systems, Fire and Gas Mapping software tools are increasingly employed.

These tools rely on specific performance criteria to analyze and optimize the placement of fire and gas detectors. For flammable gas detection mapping, one essential criterion is the size of the gas cloud or leak that needs detection. If the target gas cloud is too small, it may result in impractical, overdesigned systems that burden operators with maintenance. Conversely, if it's too large, the system may fail to detect critical containment breaches. Best practices and international guidance, such as the International Society of Automation (ISA) technical report (TR 84.00.07), offer methods for setting these criteria for hydrocarbon gas risks, but guidance for hydrogen gas risks is lacking.

Considering the growing interest in cleaner, zero-carbon hydrogen alternatives, there is a need to address the associated risks in 3D fire and gas mapping studies. Existing standards and guidance predominantly focus on hydrocarbon detection and do not adequately cover hydrogen-specific risks, such as its wider flammability range and higher ignition probability. This paper employs 3D computational fluid dynamics (CFD) explosion analysis to propose an effective strategy for defining appropriate performance targets for detecting flammable hydrogen gas. It also provides a case study to demonstrate how these targets can be used to establish a realistic and effective hydrogen gas detection system, reducing risks to As Low As Reasonably Practicable (ALARP).