Develop a Risk-Based Approach and Criteria for Hazard Detection Layout

Overview

Main Objective

The main objective of this project is to establish a performance-based methodology to optimize hazard detection layouts for LNG facilities.

Public Abstract

This project will develop a risk-based approach and criteria for hazard detection layouts at LNG facilities. The types of detectors best suited to serve different areas common to most LNG facilities will be identified and guidance will be provided on optimizing detector locations and voting logic.

Methodology This project will build off of existing guidance on hazard detection systems, such as outlined in ISA TR-84.00.07 or NORSOK Z-013, and adapt them as necessary to fit the typical layouts and hazards of onshore LNG facilities. The project team will utilize typical risk assessment methodologies available in the public domain. The methodology will be demonstrated as a case-study for a small-scale LNG liquefaction facility. Computational fluid dynamics (CFD) simulations will be utilized to perform sensitivity studies to optimize the hazard detection layout.

Summary and Conclusions

The developed methodology closely follows the performance-based design process outlined in ISA TR84.00.07. The Fire and Gas Detection Philosophy should be developed prior to assessing the facility risk or performing the hazard detector layout so that objective and unbiased performance criteria are clearly established, and all forthcoming decision-making is based on the risk tolerability of the project stakeholders. The methodology then divides the LNG facility into Detection Areas based on the hazards present and the plant layout, identifies the appropriate hazard scenarios to evaluate the detector layout, assigns performance targets within each Detection Area, and quantifies hazard detector coverage. This methodology can be utilized to develop a hazard detector layout, as well as evaluate existing layouts.

As part of this performance-based approach, risk tolerance and harm criteria are utilized to determine which scenarios need to be detected. However, it must be noted that the proposed methodology is independent of the risk tolerance and harm criteria. Therefore, users may choose to develop and/or apply different criteria but remain able to adopt this methodology as described.

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