TABLE OF CONTENTS Cross-zoned Heat Detection; Heat Detector; Detection Delay; Fire Dynamics Simulator (FDS); Aircraft Hangar; Heat Release Rate (HRR)
The following analysis considers a change from single heat detector activation to cross-zone heat detector activation to initiate a high expansion foam suppression system in an aircraft hangar. The cross-zoned implementation would be atypical in that only adjacent lines of detectors would be on different zones; detectors on the same line would be on the same zone. The hand calculations and following Fire Dynamics Simulator (FDS) runs examined the delay caused by the proposed implementation over the current and typical cross-zoning arrangements. The analysis indicated that the increase in time and heat release rate for the cross-zoned detectors was acceptable in comparison to the growth rates of the fires for the scenarios analyzed. Approval for implementation of the proposed change was granted.
The impetus for this analysis came out of the desire of an aircraft hangar owner to avoid an unintended discharge of the installed hangar fire suppression foam system. The owner's concern about an unintended discharge had been recently heightened by a high-expansion foam system activation caused by water infiltration into a manual pull station due to a piece of failed domestic plumbing equipment.
The company operates several aircraft hangars and flight operations for a fleet of business jets. Concerned...
