Heat radiation from flares

HEAT RADIATION FROM FLARES

HEAT RADIATION FROM FLARES

by: Selma E. Guigard, Ph.D. Principal Investigator Warren B. Kindzierski, Ph.D., P.Eng. Co-Investigator Nicola Harper, M.Eng. Environmental Engineering Program Department of Civil and Environmental Engineering University of Alberta Edmonton, Alberta T6G 2M8

Prepared for Science and Technology Branch Environmental Sciences DivisionAlberta Environment 9820 - 106 Street Edmonton, Alberta T5K 2J6

May 2000

Pub. No. ISBN: ISBN:

T/537 0-7785-1188-X (printed edition) 0-7785-1189-8 (on-line edition)

Although prepared with funding from Alberta Environment (AENV), the contents of this report do not necessarily reflect the views or policies of AENV, nor does mention of trade names or commercial products constituteendorsement or recommendation for use.

For further information regarding this report, contact: Information Centre Alberta Environment Main Floor, Great West Life Building 9920 – 108 Street Edmonton, Alberta T5K 2M4 Phone: (780) 944-0313

This report may be cited as: Guidard, S.E., W.B. Kindzierski and N. Harper, 2000. Heat Radiation from Flares. Report prepared for Science and Technology Branch,Alberta Environment, ISBN 0-7785-1188-X, Edmonton, Alberta.

EXECUTIVE SUMMARY Determination of the levels of thermal radiation emitted from flares is important in facility design. This information is used to site flares and to establish flare stack heights in order that workers and equipment are protected. This information is also used for air dispersion modeling in order to assess the impactto air quality from combustion byproducts released from operating flares. Knowledge of the fraction of heat radiated from flares is needed in order to determine thermal radiation levels. This report briefly reviews and summarizes theoretical and observational relationships for determining the fraction of heat radiated from flares in proximity of a flame. Nine articles are reported in which thefraction of heat radiated in proximity of a flame is determined by theoretically-derived relationships. Two articles are reported in which the fraction of heat radiated in proximity of a flame is determined by empirically-derived relationships. A matrix summarising which parameters have been used to determine the fraction of heat radiated for each of these relationships is shown below. Theapplicability of these relationships to the general case is limited. The theoretical or empirical

conditions for which many of these relationships are based upon are situation-specific. In addition, limited information was provided in many instances on numerous parameters that are known to influence flare heat radiation losses (e.g. stack exit velocity, crosswind velocity, aerodynamics of the flame,etc.).

Relationships for determination of ground-level radiation in proximity of flares are also summarized. In addition, details of field equipment and instrumentation used to measure some of the parameters required for use in the relationships for determining the fraction of heat radiated are reported.

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TABLE OF CONTENTS
EXECUTIVE SUMMARY…………………………………………………………………………………….………ITABLE OF CONTENTS……………………………………………………………………………………….…….III LIST OF TABLES…………………………………………………………………………………………………….VI LIST OF FIGURES……………………………………………………………………………………………..……...V 1 Introduction .............................................................................................................................................1 1.1 1.2 2 2.1 2.2 Objectives........................................................................................................................................3 Scope ...............................................................................................................................................3 Definition.........................................................................................................................................4...