On quantification of hydrogen cyanide in residential fire environments and its implications on occupant tenability

Ghanekar, Shruti

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https://hdl.handle.net/2142/116229 Copy

Description

Title

On quantification of hydrogen cyanide in residential fire environments and its implications on occupant tenability

Author(s)

Ghanekar, Shruti

Issue Date

2022-07-15

Director of Research (if dissertation) or Advisor (if thesis)

Lee, Tonghun

Doctoral Committee Chair(s)

Lee, Tonghun

Committee Member(s)

• Glumac, Nick G
• Kersh, Mariana E
• Kriven, Waltraud M
• Horn, Gavin P

Department of Study

Mechanical Sci & Engineering

Discipline

Mechanical Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• tunable diode laser
• absorption spectroscopy
• hydrogen cyanide
• asphyxiant gas
• full-scale realistic experiments
• residential fires
• fractional effective dose
• tenability
• laser diagnostics

Abstract

The contemporary residential environment includes configurations with large open space, lightweight construction materials and home furnishings made of complex organic compounds that produce toxic substances upon incomplete combustion in the event of an accidental fire. In addition to these, hyperthermia, low visibility, hypoxia and exposure to irritant gases and asphyxiant gases such as carbon monoxide and hydrogen cyanide in the residential fire environment pose significant health risks to potential trapped occupants as well as firefighters and other emergency response personnel. Characterizing the physical properties and composition of smoke in the residential fire environment and how the evolution of fire and firefighter intervention changes the smoke, is of utmost importance for mitigating loss of life and preventing long-term harm to all those who could potentially be exposed. Hydrogen cyanide (HCN) is a systemic poison that causes physical discomfort to humans when exposed to low concentrations and loss of consciousness or death at higher concentrations. Portable HCN measurement systems to measure the concentrations expected in the residential fire environment with short time resolution (1 Hz) are not commercially available. Therefore, a robust and versatile portable tunable diode laser based measurement system for measuring high concentrations of hydrogen cyanide in a time-resolved manner, from two locations simultaneously, is developed for application in the fire environment. The direct absorption Tunable Diode Laser Absorption Spectroscopy (TDLAS) technique is employed for quantification of HCN using the R11 absorption line centered at 3345.3 cm-1 (2989.27 nm) in the fundamental symmetric stretching band of the HCN absorption spectrum. The design, validation and application of this HCN measurement system is described in detail in this dissertation. After validating the measurement system in the lab, the robustness and portability of the one-location HCN measurement system is tested on the fireground in quasi-controlled experiments with a real residential fuel in a series of three experiments conducted in the Fireground Exposure Simulator (FES) prop at the University of Illinois Fire Service Institute, Champaign, IL. The time resolved HCN concentrations measured at 0.3 m, 0.9 m and 1.5 m heights in these experiments are presented and discussed. The HCN measurement system is then expanded to measure concentration from two locations and deployed in a series of 21 carefully controlled full-scale experiments designed to recreate realistic residential fires in single-story residential structures. These experiments are conducted at Delaware County Emergency Services Training Center, Sharon Hill, PA, in two identical ranch-style single story residential structures, each consisting of four bedrooms with attached bathrooms and closets, a kitchen and a living room. All the rooms in the structures are fully furnished with a typical residential fuel load. Time-resolved measurements of HCN in gas sampled from two locations for each experiment are presented and discussed in detail. These measurements represent one of the first attempts to quantify high concentrations of HCN in realistic residential fire environments using an optical laser-based technique with a time resolution of 1 Hz and are a significant addition to the ever-growing repository of experimental measurements of the fire environment. Finally, tenability analysis of locations where HCN is measured in the full-scale residential fire experiments conducted demonstrates the importance of time-resolved HCN measurements to precisely evaluate the risks due to asphyxiant gas exposure to potential trapped occupants in the residential fire environment as the gas concentrations can transition to lethal levels within few seconds.

Graduation Semester

2022-08

Type of Resource

Thesis

Copyright and License Information

Copyright 2022 Shruti Ghanekar

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