This engineering practice Guide, based on the DETACT-QS program, describes a model for predicting the response time of ceiling-mounted heat detectors/sprinklers and smoke detectors, installed under large unobstructed ceilings, for fires with user-defined, time-dependent heat release rate curves. The Guide provides information on the technical features, theoretical basis, assumptions, limitations, and sensitivities as well as guidance on the use of DETACT-QS. Evaluation is based on comparing predictions from DETACT-QS with results from full-scale fire experiments conducted in compartments with ceiling heights ranging from 2.44 m (8 ft) to 12.2 m (40 ft) and peak fire heat release rates ranging from 150 kW to 3.8 MW. Use of this model with building geometries or fire characteristics other than those used in this evaluation may require further evaluation or testing.
Author(s): Society for Fire Protection Engineers
Series: The Society of Fire Protection Engineers Series
Publisher: Springer
Year: 2021
Language: English
Pages: 183
City: Cham
The SFPE Task Group on Computer Model Evaluation
Acknowledgment
Contents
List of Figures
List of Tables
Introduction
Disclaimer
Purpose
Model Description
Definitions
Model Uses and Predictions
Type of Model
Model Complexity
Physics of Model
Minimum Hardware Requirements
Operating System
Model Assumptions
Input Data Required
Property Data
Principal Publications Supporting DETACT-QS
Scenarios for Which Evaluation Is Sought
Quantities Predicted by the Model (Output)
Degree of Accuracy
Variability and Uncertainty of Fire Test Data
Variability and Uncertainty in the Model
Variability and Uncertainty of Model Input Parameters
Overall Degree of Accuracy Required
Theoretical Basis for the Model
Inputs for DETACT-QS Algorithm
Derivation of the Sprinkler Response Equation
Solution in DETACT-QS
Mathematical and Numerical Robustness
Code Evaluation
Detector Temperature
Time to Activation
Independent Comparison of DETACT-QS Results
Summary
Model Sensitivity
Variables
Acceptable Range of Values of Input Parameters
Quantification of Sensitivity
Sensitivity Analysis: Phase One
Sensitivity Analysis: Phase Two
Sensitivity Analysis: Phase Three
Cautions
Model Inputs
Evaluation Scenarios 1–6
Geometry and Materials
Fire Source
Instrumentation
Evaluation Scenario 7
Evaluation Scenarios 8–16
Geometry and Materials
Fire Source
Instrumentation
Property Data
Numerical Constants
Model Evaluation
Evaluation Scenarios 1 Through 6—Results
Scenario 1—3.0 M Ceiling Height
Scenario 2—4.6 M Ceiling Height
Scenario 3—6.1 M Ceiling Height
Scenario 4—7.6 M Ceiling Height
Scenario 5—10.7 M Ceiling Height
Scenario 6—12.2 M Ceiling Height
Creation of a Hot Layer During Testing
Evaluation Scenario 7
Plume and Ceiling Jet Temperature Correlation Analysis
Evaluation Scenarios 8 Through 16
Summary of Analysis
Addressing Uncertainty and Variability by Use of Multiplication Factors
Limitations/User Guidelines
Limitations
Use of DETACT-QS to Model Smoke Detector Activation
Uncertainty when Using DETACT-QS
Appendices
Appendix A: Mathematical Solver Worksheet—Independent Solutions for DETACT-QS Response
Introduction
Solution
Definitions of Variables
Fire Specification
Ceiling Jet Temperature
Ceiling Jet Velocity
Link Temperature
Time to Activation
Results
Time to Detector Activation
Predicted Detector Temperatures and Gas Temperatures
Appendix B: Data Used for Sensitivity Analysis
References
