(53n) An Engineered Approach for Developing the Fire and Gas Layouts By Application of 3-Dimensional Fire and Gas Mapping Study to Improve the Effectiveness of the Detection System

Fire and Gas detector mapping has become an important process safety tool in Process Industries especially in Oil and Gas sector due to the fact that these facilities handle highly flammable materials and substantial equipment’s in highly congested areas posing heavy risk to personnel working, environment and public surrounding the facility. A well-configured F & G system will enable immediate detection (Early Detection) & isolation and expedite timely escape and evacuation of personnel.

Normally F&G mapping study should be conducted in the design stage to ensure detector coverage targets are met inherently. Moreover, during normal operation, this study should be carried out when there are major changes or modifications in the facility.

For Fire and gas detection systems to be efficient, it is important that they offer a high chance of detecting the presence of any flame and gas hazards within monitored process areas. Determining optimal quantity and location of flame and gas detectors is therefore critical to ensure the detection system’s effectiveness. This paper examines various aspects of fire and gas detection, identifying the gaps and inconsistencies that exist in the detector layout developed based on conventional (2D F&G) approaches with a supporting case study.

This paper tries to address two main hazards i.e., 1) Accumulation of toxic gas levels exceeding exposure threshold limits and 2) Accumulation of flammable gases to levels that can cause fire or explosion, involving critical factors like properties of the material being handled, geographical location of the release scenarios, weather parameters to analyse dispersion patterns, and obstruction levels. This paper also compares the methodology and advantages / shortcomings in optimising the no. of detectors in 2D and 3D F & G modelling.

The results conclude that the 3D approach (Geographical) for Fire and Gas detection system is most effective method which will better optimise the number of detectors being used with high probability in detecting the hazardous material in case of an LOC event and location of detector considering maintenance access and height of the detector etc. Also this method will use to avoid the bypassing of detector without proper review as it is normally included in SIS for the effective operation. This in turn proves to be cost effective method and improving the life cycle of the detector over 2D, which does not address the percentage of area covered by the flame or gas detectors.