CONDUCTING A FULL FACTORIAL COMPUTATIONAL EXPERIMENT TO DETERMINE THE FIRE TEMPERATURE REGIME IN A VERTICAL CABLE TUNNEL OF A NUCLEAR POWER PLANT
Abstract
The research of the fire temperature regime is a relevant issue because vertical cable tunnels differ in geometric configuration, the types of cables they contain, fire loads, and aerodynamic characteristics. This can lead to variations in the fire temperature regime within such tunnels, both compared to the standard fire temperature regime and among themselves. To address these challenges, conducting a full factorial computational experiment to determine the fire temperature regime on full-scale models constructed using the Fire Dynamics Simulator software is a viable solution. These models have been verified and checked for adequacy compared to actual full-scale fire tests conducted on constructed models. In order to identify the most significant parameters of the vertical cable tunnel that influence the fire temperature regime and the range of their variations, seventeen computational experiments were conducted. According to the obtained results, the most influential factors affecting the maximum temperature, the time to reach it, and the duration it is maintained are three: fire load, height, and the longitudinal cross-sectional area.
A complete factorial experiment was developed and carried out to obtain a regression of the maximum temperature, fire duration, and time to reach the maximum temperature. With a cable insulation load of 10 kg per meter of cable height in cable lines made of polyvinyl chloride, the maximum temperature exceeded 1200°C and reached values of 1400°C, while with the lowest load at 1 kg per meter of cable height, it reached 400°C. This temperature reached its maximum values 48% faster than with the maximum load. With the smallest cross-sectional area and a reduced height of the vertical cable tunnel, the temperature inside decreased to 50% of the maximum possible variant, and the time to reach the maximum temperature increased by 65%. When further assessing the fire resistance of building structures, the obtained fire temperature regime should be chosen in accordance with the conducted full factorial experiment.
