1、API PUBL*:4628 96 0732270 0559953 98T American Petroleum documenting performance improvements; and communicating them to the public. The foundation of STEP is the API Environmental Mission and Guiding Environmental Principles. API ENVIRONMENTAL MISSION AND GUIDING ENVIRONMENTAL PRINCIPLES The member
2、s of the American Petroleum Institute are dedicated to continuous efforts to improve the compatibility of our operations with the environment while economically developing energy resources and supplying high quality products and services to consumers. The members recognize the importance of efficien
3、tly meeting societys needs and our responsibility to work with the public, the government, and others to develop and to use natural resources in an environmentally sound manner while protecting the health and safety of our employees and the public. To meet these responsibilities, API members pledge
4、to manage our businesses according to these principles: *:e To recognize and to respond to community concerns about our raw materials, products and operations. e:* To operate our plants and facilities, and to handle our raw materials and products in a manner that protects the environment, and the sa
5、fety and health of our employees and the public. *:* To make safety, health and environmental considerations a priority in our planning, and our development of new products and processes. e:+ To advise promptly, appropriate officials, employees, customers and the public of information on significant
6、 industry-related safety, health and environmental hazards, and to recommend protective measures. *:* To counsel customers, transporters and others in the safe use, transportation and disposal of our raw materials, products and waste materials. *:+ To economically develop and produce natural resourc
7、es and to conserve those resources by using energy eificiently. +:e To extend knowledge by conducting or supporting research on the safety, health and environmental effects of our raw materials, products, processes and waste materials. e:* To commit to reduce overall emission and waste generation. +
8、:* To work with others to resolve problems created by handling and disposal of hazardous substances from our operations. +3 To participate with government and others in creating responsible laws, regulations and standards to safeguard the community, workplace and environment. +:e To promote these pr
9、inciples and practices by sharing experiences and offering assistance to others who produce, handle, use, transport or dispose of similar raw materials, petroleum products and wastes. API PUBL*4b28 96 = 0732290 0559953 752 W A Guidance Manual For Modeling Hypothetical Accidental Releases to the Atmo
10、sphere Health and Environmental Sciences Department API PUBLICATION NUMBER 4628 PREPARED UNDER CONTRACT BY JAMES H. MOSER, PH.D. PO Box 898 CYPRESS, TX 7741 0-0898 JAMES MOSER RESEARCH, INC. NOVEMBER 1996 American Petroleum Institute API PUBLX4628 96 m 0732290 0559954 699 m FOREWORD API PUBLICATIONS
11、 NECESSARILY ADDRESS PROBLEMS OF A GENERAL NATURE. WITH RESPECT TO PARTICULAR CIRCUMSTANCES, LOCAL, STATE, AND FEDERAL LAWS AND REGULATIONS SHOULD BE REVIEWED. API IS NOT UNDERTAKING TO MEET THE DUTIES OF EMPLOYERS, MANUFAC- TURERS, OR SUPPLERS TO WARN AND PROPERLY TRAIN AND EQUIP THEIR EMPLOYEES, A
12、ND OTHERS EXPOSED, CONCERNING HEALTH AND SAFETY RISKS AND PRECAUTIONS, NOR UNDERTAKING THEIR OBLIGATIONS UNDER LOCAL, STATE, OR FEDERAL LAWS. NOTHING CONTAINED IN ANY API PUBLICATION IS TO BE CONSTRUED AS GRANTING ANY RIGHT, BY IMPLICATION OR OTHERWISE, FOR THE MANU- FACTURE, SALE, OR USE OF ANY MET
13、HOD, APPARATUS, OR PRODUCT COV- THE PUBLICATION BE CONSTRUED AS INSURING ANYONE AGA3NST LIABIL- ERED BY LETTERS PATENT. NEITHER SHOULD ANYTHING CONTAINED IN ITY FOR INFRINGEMENT OF LETTERS PAENT. Copyright O 1996 American Petroleum Institute API PUBLU4628 96 0732290 0559955 525 CONTRACTORS ACKNOWLED
14、GMENTS he author wishes to recognize and thank the following people for their contributions of time T and expertise during this study and for their support in the development of this document. Many technical and editorial contributions were made which enhanced the content of the Manual as well as it
15、s organization: Mr. K. W. Steinberg, Exxon Research and these members of the Air Modeling Task Force: Doug N. Blewitt, Amoco Corporation, Richard W. Carney, Phillips Petroleum Company, Mark W. Deese, Phillips Petroleum Company, David J. Fontaine, Chevron Research her assistance was invaluable. API P
16、UBLr4628 b 0732290 0555b 4bL PREFACE his manual presents methods for modeling hypothetical accidental releases of fluids into the T atmosphere fiom petroleum process operations. Given a particular type of release (e.g., pipe break, evaporating pool) and the chemicals or petroleum fractions involved,
17、 methods for modeling the release and subsequent dispersion phenomena are treated in a step-wise, comprehensive manner. The reader is presumed to be technically oriented, but not a specialist in the various disci- plines represented. Release phenomena, germane meteorological concepts, and after-the-
18、fact mitigation countermea- sures are presented for ready reference in this document. First, fluid dynamic and thermodynamic procedures best used to calculate flow rates and initial fluid states for a material being released into the atmosphere are given in some detail, including numerical examples.
19、 Next, the essential information required to characterize the atmosphere for dispersion modeling is presented, along with recommended default parameters. Lastly, available quantitative methods for incorporating vapor cloud mitigation methods into the dispersion modeling are presented. To demonstrate
20、 how a number of the modeling procedures can be implemented, detailed simulation of eight hypothetical release scenarios are presented. The assumptions made, the calculation and/or selection of appropriate modeling parameters, use of several well-known modeling programs, and graphical presentation o
21、f results obtained are discussed. It is not possible to present all the information that might be required for the various disciplines involved; however, extensive references are provided. API PUBLx4b28 9b 0732290 0559957 3T8 TABLE OF CONTENTS NOMENCLATURE . N-i CHAPTER ONE: Introduction Manual Orga
22、nization 1-2 Quick References . 1-3 Terminology . 1-4 Subject Index Development . 1-4 Conventions . 1-3 CHAPTER TWO: Overview of ReleaseDispersion Processes and Demonstration Scenarios The Overall Modeling Process . 2-1 Near vs Far Field Modeling . 2-2 Release-to-Dispersion Phenomena 2-3 Demonstrati
23、on Scenarios . 2-4 1 : Hydrogen Sulfide from Unlit Flare Stack 2-7 2: Hydrogen Sulfide and Carbon Dioxide from a Safety Relief Stack 2-7 3: Supercritical Propane Pipe Hole Release 2-7 4: Oil Well Blowout 2-8 5: Liquified Chlorine Tank Truck Accident 2-8 6: Ammonia Hose or Pipe Break . 2-9 7: Hydroge
24、n Chloride Pipe Break 2-9 8: Evaporating Pool of Liquid Benzene . 2-9 CHAPTER THREE: Source Modeling Overview 3-1 Units of Measure 3-2 Phase Equilibria 3-2 PhaseRule 3-2 Release Characterization Complexities 3-1 . Pure Component Systems . 3-3 Multicomponent Vapor-Liquid Equilibria 3-4 Ideal VLE (Fla
25、sh) Calculations 3-6 Flash Calculation Algorithm 3-8 Volumetric Properties of Pure Fluids . 3-11 The Virial Equation of State for Gases . 3-11 The Ideal Gas Law . 3-11 Cubic Equations of State 3-11 Generalized Correlations for Liquids . 3-12 Thermodynamic Properties 3 . 12 Other Properties 3 . 13 Di
26、scussion 3-5 Fluid Properties 3-11 . API PUBLX4628 96 W 0732290 0559958 234 m Contents Chapter 3 (continued) Viscosity 3-13 Molecular Difksivity . 3-14 Surface Tension . 3-14 Mixture Bulk Properties. Pseudo-Pure Components and Average Values 3-14 General References . 3-16 On-Line Computer Services .
27、 3-17 Process Flowchart Simulators 3-17 Thermodynamics of Fluid Depressurization 3-19 Basic Premises and Equations 3 . 19 Conservation of Mass 3-19 General Steady State Energy Balance . 3-20 Superheated Gases . . 3-24 Two Phase Fluid Densities . 3-25 Instantaneous Flashing Releases 3-25 Desktop Refe
28、rences 3-16 Conservation of Energy . 3-20 Flashing Liquid . 3-26 Vapor Condensation 3-26 Approximate Isenthalpic Methods . 3-27 Flow Rate Estimation . 3-29 Introduction 3-29 Critical Pressure Ratio 3-30 A General Model for Choked Flow 3-31 Choked Flow of an Ideal Gas 3-32 Non-Choked Gas Flow 3-33 No
29、n-Flashing Liquid Flow . 3-34 Flashing Liquid Flow . 3-35 Fauske and Epstein 3-36 LeungandGrolmes 3-37 Leung1992 3-38 Comparison of Methods . 3-40 Conclusions 3-42 Flow from Pipes . 3-45 Initial Jet Expansion 3-47 General Considerations . 3-47 Modell 3-48 Model2 . 3-48 Comparison of Methods 3-49 Exa
30、mple Calculations . 3-50 Vapor-Only Jet (example) . 3-50 Flashing Liquid Jet (example) 3-50 Evaporation . 3-53 Initial Jet Expansion Models . 3-47 API PUBL*4628 96 0732290 OSSSS 170 Contents Chapter 3 (continued) Introduction 3-53 Evaporation Model Survey 3-54 SpillRates . 3-57 Aerosol Formation 3-5
31、7 Governing Phenomena . 3-57 Rainout Algorithm 3-58 Size and Shape of Pools 3-59 Concepts 3-59 A General Model . 3-59 Approximate Models 3-60 Model Components 3-61 Evaporative Mass Transfer 3-61 Evaporative Heat Flux . 3-62 Air to Pool Heat Transfer . 3-62 SolarHeating 3-63 Radiative Cooling . 3-64
32、Heat Transfer fi-om the Ground 3-64 Numerical Example 3-67 CHAPTER FOUR: Meteorology Modeling Parameters 4-3 Boundary Layer 4-3 Roughness Length Estimation 4-4 Wind Direction 4-7 WindSpeed . 4-7 Ambient Temperature. Pressure. and Relative Humidity 4-8 Averaging Time . 4-9 Plume Buoyancy Criteria . 4
33、-11 AtrnosphericStability . 4-5 Release Duration 4-10 CHAPTER FIVE: Mitigation Countermeasure Modeling Introduction . 5-1 Passive Barriers 5-1 Active Barriers 5-2 Review of Plume Mitigation Methods 5-1 Water Spray Curtains - No Removal . 5-2 Water Spray Curtains - With Removal . 5-3 Fire Monitors .
34、5-5 Spray Removal of Non-Volatile Aerosols . 5-5 Steam Curtains 5-5 Foams . 5-6 API PUBL*qb28 96 W 0732290 05599bO 992 Contents Chapter 5 (continued) Release Duration Control . 5-6 Estimation of Plume Modification Parameters . 5-7 Air Entrainment Dilution Devices 5-8 General Relationships . 5-8 Wate
35、r Sprays - Downward Pointing Nozzles . 5-9 Water Sprays . Upward Pointing Nozzles . 5-10 Water Sprays . Other Orientations Removal of Released Material 5-11 Spray Barrier Removal Modeling Programs . 5-12 Scope 5-7 5-11 General 5-11 Scrubbing Efficiency of Spray Curtains and Firewater Monitors . 5-11
36、 CHAPTER SIX: Analysis and Simulation of Release Scenarios Introduction 6-1 1: Hydrogen Sulfide from Unlit Flare Stack Statement 51-1 Analysis 51-1 Other Parameters 51-2 Simulation 51-2 . Stack Gas Physical Property Parameter Estimation 51 . 1 SLAB 51-2 DEGADIS . 51-4 HGSYSTEM 51-5 2: Hydrogen Sulfi
37、de and Carbon Dioxide from a Safety Relief Stack Statement 52-1 Analysis 52-1 Other Parameters 52-2 Simulation 52-3 . SourceRelease Parameters . 52-1 Other Modeling Programs . 52-4 3: Supercritical Propane Pipe Hole Release Statement 53-1 Analysis 53-1 . SourceRelease Parameters . 53-1 Atmospheric P
38、arameters . 53-3 Simulation 53-3 ModelType 53-3 Conclusions 53-4 . API PUBL*4b28 96 W 0732290 0559961 829 W Contents Chapter 6 (continued) 4: Oil Well Blowout Statement SourceRelease Parameters Analysis . Pseudo-Pure Component Properties Estimation Atmospheric Parameters Simulation . Two-Phase Relea
39、ses . DEGADISModeiing Vapor-Only Release Modeling . Conclusions 54-1 54-1 54-1 54-2 54-3 54-3 54-3 54-4 54-4 54-5 5: Liquified Chlorine Tank Truck Accident Statement 55-1 Analysis . 55-1 Source Characterization . 55-1 Atmospheric Parameters 55-1 Discussion . 55-2 Simulation . 55-2 6: Ammonia Hose or
40、 Pipe Break Statement 56-1 Analysis 56-1 . Thermodynamic Considerations 56-1 Other Parameters 56-3 Simulation . 56-3 7: Hydrogen Chloride Pipe Break Introduction 57-1 Scenario Description . 57-1 Source and Spray Curtain Parameters 57-2 Release Rate . 57-2 Turbulent Jet Simulation 57-2 HEGADAS Air Di
41、spersion Simulations 57-4 Steady State and Finite Duration Simulations . 57-4 Time Dependent Simulation . 57-5 Water Spray Curtain Plume Modification Parameters . 57-3 Conclusions 57-6 8: Evaporating Pool of Liquid Benzene Statement 58-1 Analysis . 58-1 API PUBL*462 96 m 0732290 0559962 i65 Contents
42、 Chapter 8 (continued) SourceRelease Parameters . 58-1 Other Parameters 58-2 Simulation 58-2 REFERENCES . R-1 Chapter 3: Source Modeling R-1 Chapter 4: Meteorology R-6 Chapter 5: Mitigation Countermeasures . R-7 Chapter 6: Analysis and Simulation of Release Scenarios R-10 Appendix II: Modeling Progr
43、ams . R-10 APPENDIX I: Recommended Default/Starting Values for Modeling Parameters 1-1 APPENDIX II: Overview of Scenario Modeling Programs Submodels .I 1.1 Turbulent Jets and Far-Field Plumes II- 1 HGSYSTEM 1-2 SLAB 1-3 DEGADIS .I 1-3 . . . Dense Gas Models .I 1-3 Evaporation Submodels -11-4 .I 1-5
44、Time Dependent Modeling . SLAB 1-5 HGSYSTEM 1-5 DEGADIS I 1-6 SLAB 1-6 HGSYSTEM 1-7 DEGADIS . 1-7 Thermodynamic and Physical Properties .I 1-6 . Program Output -11-7 New Version of HGSYSTEM 11-7 APPENDIX III: HGSYSTEM File Listings for Scenario 7 111-1 INDEX Index-1 API PUBLu4628 96 = 0732290 055996
45、3 bTL FIGURES AND TABLES I . Figures Chapter 2: Overview of ReleaseLDispersion Processes and Demonstration Scenarios 1 . Paths to Air Dispersion Near the Release Point . 2-3 2 . Release Paths for Scenarios 1,2, and 3 . 2-7 3 . Release Paths for Scenarios 4.6. and 7 . 2-8 4 . Release Paths for Scenar
46、io 5 . 2-8 5 . Release Path for Scenario 8 2-9 Chapter 3: Source Modeling 1 . 2 . BinaryVLEDiagram 3-5 3 . 4 . Critical Pressure Ratio Definitions 3-30 5a,b . 6 . 7. 8 . 9 . 1 O . Heat Conduction Model 3-65 Equilibrium Vapor Pressures . 3-3 Control Volume Example 3-19 Flashing Choked Flow Methods .
47、3-41 High and Low Subcooling: Leung 3-43 Non-Flashing and Flashing Flow: Leung 3-44 Expanding Jet Force Balance 3-49 Evaporating Pool Mass and Energy Flows . 3-53 . . Chapter 4: Meteorology 1 . Incident Wind Profile Diagram 4-1 2 . 3 . Stability Class and Plume Height 4-6 4 . 5 . Humidity Effect of
48、Air Density 4-9 6 . . Roughness Length vs . Site Classification . 4-4 Pressure and Temperature vs Height . 4-8 Concentration Time Series . 4-9 . . Chapter 5: Mitigation Countermeasure Modeling 1 . 2 . 3 . 4 . 5 . 6 Dilution-Only Mitigation by a Spray Barrier: Meroney 5-2 ICHMAP HF Water Spray Study
49、. 5-3 . Spray Curtain Removal: Meroney 5-4 Spray Curtain Removal with Entrainment: Meroney 5-4 Finite Duration Releases . 5-6 . Overhead View of Intercepted Plume 5-7 Steady State Concentration Correction Factors for Constant Rate, Chapter 6: Scenario 1 1 . Plume Centerline Paths 51-3 2 . SLAB H2S Concentrations 51-4 API PUBL*4628 96 0732290 0559964 538 Figures and Tables Figures (continued) Chapter 6: Scenario 2 1 . Initial DEGADIS Distance 52-3 2 . 3 . 4 . Final Plume Centerline Elevations 52-4 . Search for Acceptable Stack Height $2-3 Final Centerline Ground Level Concentrations 52
