Analysis on the Fire Growth Rate Index Considering of Scale Factor, Volume Fraction, and Ignition Heat Source for Polyethylene Foam Pipe Insulation

• Main Authors: Jung Wook Park, Ohk Kun Lim, Woo Jun You
• Format: Article
• Language: English
• Published: MDPI AG 2020-07-01
• Series: Energies
• Subjects: pipe insulation; fire growth rate index; scale factor; volume fraction; ignition heat source; maximum heat release rate
• Online Access: https://www.mdpi.com/1996-1073/13/14/3644

The fire growth rate index (<i>FIGRA</i>), which is the ratio of the maximum value of the heat release rate (<i>Q_max</i>) and the time (<i>t_max</i>) to reach the maximum heat release rate, is a general method to evaluate a material in the fire-retardant performance in fire technology. The object of this study aims to predict <i>FIGRA</i> of the polyethylene foam pipe insulation in accordance with the scale factor (<i>S_f</i>), the volume fraction of the pipe insulation (<i>VF</i>) and the ignition heat source (<i>Q_ig</i>). The compartments made of fireboard have been mock-up with 1/3, 1/4, and 1/5 reduced scales of the compartment as specified in ISO 20632. The heat release rate data of the pipe insulation with the variation of <i>S_f</i>, <i>VF,</i> and <i>Q_ig</i> are measured from 33 experiments to correlate with <i>FIGRA</i>. Based on a critical analysis of the heat transfer phenomenon from previous research literature, the predictions of <i>Q_max</i> and <i>t_max</i> are presented. It is noticeable that the fire-retardant grade of the polyethylene foam pipe insulation could have Grade B, C, and D in accordance with the test conditions within ±15% deviation of the predicted <i>FIGRA</i>. In case of establishing the database of various types of insulation, the prediction models could apply to evaluate the fire-retardant performance.