Fire & Gas Mapping: Actual Engineering or Fancy Computer Aided Graphics ?

With the relatively new and growing interest in design of Fire & Gas systems using computer-aided mapping for detector placement, these software tools are rapidly evolving.   Full disclosure here; Kenexis develops and licenses a very good software tool called Effigy™ for Fire & Gas Mapping, which is a component of the Kenexis Integrated Safeguard Suite.  I’ve recently had interactions with engineers who have worked with our software as well as competing products.  These users often describe the challenge of obtaining an accurate 3D representation of the process so that fire & gas mapping (in particular, flame detector mapping) can be done with the level of precision required by engineers.  The goal is to ensure that detectors are located in areas where they provide good coverage and are not obstructed by other equipment.  For a large greenfield project we probably will have access to a sophisticated 3D process model (e.g., PDMS, AutoCAD, etc.) developed by the engineering contractor, which can be imported into the mapping software.  However, occasionally this is not available especially for brownfield Fire & Gas upgrades, and we need to develop a 3D model within the mapping software itself.  In these cases the starting point should be an accurate field survey of an existing plant with 2D layout drawings (plan and profile) as well as an accurate plant coordinate system.  Of the commercially available mapping tools, there are a couple of different ways to generate this 3D representation of process equipment, structures, and any other obstructions that would significantly impact detector coverage.  Kenexis’ Effigy™ uses plant-coordinate system data for entering these type of user-defined objects.  Some competing tools have a user interface more akin to a computer aided graphics package like “Paint” or “SketchUp”.   The attractiveness of a graphical interface that allows ‘drawing’ of plant equipment is obvious; however, let’s consider the implications of generating quick / easy  computer graphics.  Moreover, I’m even aware that some software designers are considering ‘extruding’ a 2D layout drawing into 3D space.  Interesting concepts for sure, but does it sound a bit like a process plant edition of a Sims™ game?

Above all else, this is engineering design of safety-critical instrumentation & control equipment.  These are life-safety systems we are designing or altering.  Like many of my colleagues at Kenexis, I am a licensed Professional Engineer (PE), which means I have a duty to understand the model of the physical world used in my engineering design.  Kenexis is an engineering services company that also licenses engineering software tools.  Effigy™ was created by engineers who use these calculations every day to design fire & gas systems for process plants.  These professionals are experienced in design of critical instrumentation & controls for process plants; their foundation is not vector graphics.  Effigy™ is performing engineering calculations that determines the ability to sense a threshold hazard by an array of detection equipment.  These are high fidelity calculations in 3D space.  We are not just shooting vector arrays and looking for shadows behind obstacles that were extruded from a 2D layout.  Effigy™ has sophisticated graphics to represent our model, calculations, and results in 3 dimensions; however, it’s the underlying engineering equations and algorithms that are foundation upon which the graphics can be built on top. 

 When I started work in the process safety field in 1992, I used software for Quantitative Risk Analysis (QRA) that was sophisticated in terms engineering equations to predict gas dispersion and human impact, but it was very primitive graphically.  None-the-less, the original PHAST™ and SAFETI™ models (now licensed by DNV GL) were well accepted engineering tools to make decisions about tolerable risk.  Thankfully, technology has advanced and we can study detector layout in a much more sophisticated method. However; let’s remember that sophisticated graphics are not the driver here. The importance of making informed engineering decisions comes first; 3D graphical interfaces are very useful but icing on top of the cake.