A Review of Modelling and Simulation Methods for Flashover Prediction in Confined Space Fires

Confined space fires are common emergencies in our society. Enclosure size, ventilation, or type and quantity of fuel involved are factors that determine the fire evolution in these situations. In some cases, favourable conditions may give rise to a flashover phenomenon. However, the difficulty of handling this complicated emergency through fire services can have fatal consequences for their staff. Therefore, there is a huge demand for new methods and technologies to tackle this life-threatening emergency. Modelling and simulation techniques have been adopted to conduct research due to the complexity of obtaining a real cases database related to this phenomenon. In this paper, a review of the literature related to the modelling and simulation of enclosure fires with respect to the flashover phenomenon is carried out. Furthermore, the related literature for comparing images from thermal cameras with computed images is reviewed. Finally, the suitability of artificial intelligence (AI) techniques for flashover prediction in enclosed spaces is also surveyed.This work has been partially funded by the Spanish Government TIN2017-89069-R grant supported with Feder funds. This work was supported in part by the Spanish Ministry of Science, Innovation and Universities through the Project ECLIPSE-UA under Grant RTI2018-094283-B-C32 and the Lucentia AGI Grant

Modelling and Simulation of a Novel Liquamatic Fire Monitor A fully automated fire recognition- and suppression system based on infrared machine vision technology

Masteroppgave i mekatronikk - Universitetet i Agder, 2015Background: Fire monitors are effective fire extinguishing apparatuses which combine high accuracy with long range. As part of the mechatronic trend, research has during recent years started to delve into the automation of re monitors. This involves proper actuation and control of re monitors in order to extinguish re. Up to this point, however, research has primarily been concerned with indoor operation. The aim of the present thesis is to develop a system for an electrically actuated re monitor which detects, localizes and suppresses re in an outdoor environment without the need for manual operation. Solution & Experiments: Fire is localized with computer analysis of IR stereo camera images. Based on the position of the re, mathematical models found in literature are used to determine the optimum con guration of the monitor in order to extinguish the re. Servomotors which actuate the monitor are modelled and simulated in real time using a HIL setup. A PLC is programmed to generate control signals to the servomotors. The accuracy of the stereo vision system is tested experimentally by estimating the distance to a live re at distances between 30 and 60 m. In addition, the system's ability to distinguish a re from other hot objects is tested. Liquid jet trajectory models are obtained from relevant research papers found in open literature. Parameters from these models are determined based on experiments conducted outdoors with a re monitor where wind disturbances are measured. Results: The stereo vision system exhibited a maximum error of 0.5 m or 1.6 %. The vision system is successful in distinguishing between a wooden re, a person and a pot with boiling water. The best model to predict jet trajectories found in literature yields an average error of 1.6 m from measured data with little wind present, and 9.8 m mean deviation with comparatively strong wind disturbances. Simulations are carried out with only minor discrepancies with one of the models implemented on the PLC. Conclusion: Computer algorithms which localize re in conjunction with IR cameras has been designed. The limiting factor with regards to the system's accuracy is precise predictions of the water jet's travel. The accuracy of the trajectory models as compared to experimental data measured under presented circumstances are of limited use. In addition, there are marginal di erences between the presented trajectory models found in literature, and therefore either one may be used. A PLC program has been created. HIL simulations are carried out with only minor discrepancies as compared to the predicted trajectories from one of the models