pgs2-1997 methods for the calculation of physical effects chapter 1 general introiduction

7/30/2019 PGS2-1997 Methods for the Calculation of Physical Effects Chapter 1 General Introiduction

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PUBLICATIEREEKS

GEVAARLIJKE STOFFEN

Methods for

the calculation of

physical effects

2


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Publicatiereeks Gevaarlijke Stoffen 2

Methods for the calculation

of Physical Effects

Due to releases of hazardousmaterials (liquids and gases)


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I

Methods for the calculation ofphysical effects

due to releases of hazardous materials (liquids and gases)

Yellow Book

CPR 14E

Editors: C.J.H. van den Bosch, R.A.P.M. Weterings

This report was prepared under the supervision of the Committee for thePrevention of Disasters and is published with the approval of

The Director-General for Social Affairs and EmploymentThe Director-General for Environmental ProtectionThe Director-General for Public Order and SecurityThe Director-General for Transport

The Hague, 1996

The Director-General for Social Affairs and Employment

Committee for the Prevention of Disasters

Third edition First print 1997Third edition Second revised print 2005


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TNO

II

Research performed by TNO - The Netherlands Organization of Applied Scientific Research

List of authors

Chapter 1. General introduction Ir. C.J.H. van den Bosch

Dr. R.A.P.M. Weterings

Chapter 2. Outflow and Spray release Ir. C.J.H. van den Bosch

Ir. N.J. Duijm

Chapter 3. Pool evaporation Ir. C.J.H. van den Bosch

Chapter 4. Vapour cloud dispersion Dr. E.A. Bakkum

Ir. N.J. Duijm

Chapter 5. Vapour cloud explosion Ir. W.P.M. MercxIr. A.C. van den Berg

Chapter 6. Heat flux from fires dIr. W.F.J.M. Engelhard

Chapter 7. Ruptures of vessels Mrs. Ir. J.C.A.M. van Doormaal

Ir. R.M.M. van Wees

Chapter 8. Interfacing of models Ir. C.J.H. van den Bosch

Annex Physical properties of chemicals Ir. C.J.H. van den Bosch


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III

Contents

Preamble

Preface

Revision history

1. General introduction

2. Outflow and Spray release

3. Pool evaporation

4. Vapour cloud dispersion

5. Vapour cloud explosion

6. Heat flux from fires

7. Rupture of vessels

8. Interfacing of m odels

Annex Physical propert ies of chemicals


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IV

Preamble

When the first edition of this Yellow Book was issued, it contained

calculation meth ods to be performed on pocket calculators.

Although the second edition in 1988 presumed that personal computers would be

available to perform the required calculations, only part of the report was u pdated.

T oday more powerful comp uters are generally available, thus enabling the use of

more complex and more accurate computing models.

This third edition is a complete revision by TNO Institute of Environmental

Sciences, Energy Research and Process Innovation. It is based on the use of these

powerful PCs and includes the application of proven computing models. Special

attention is paid to provide adequate directions for performing calculations and forthe coupling of models and calculation results.

T he revision of the Yellow Book was supervised by a committee in which

participated:

Dr. E.F. Blokker, chairman Dienst Centraal Milieubeheer Rijnmond

Mr.Ir. K. Posthuma, secretary Ministerie van Sociale Zaken en Werkgelegenheid

D r. B.J.M . Ale Rijksinstituut voor Volksgezondheid en Milieu

Drs. R. Dauwe DOW Benelux N.V.

Ir. E.A. van Kleef M inisterie van Binnenlandse Zaken

Mrs. Ir . M.M. Kruiskamp Dienst Centraal Milieubeheer Rijnmond

D r. R.O .M . van Loo M in isterie van Volkshu isvestin g, Ru im telijkeOrd ening en Milieubeheer

In g. A.J. M uyselaar M in isterie van Volkshu isvestin g, Ru im telijke

Ord ening en Milieubeheer

Ing. H .G. Roodbol Rijkswaterstaat

Drs.Ing. A.F.M . van der Staak Ministerie van Sociale Zaken en Werkgelegenheid

Ing. A.W. Peters M inisterie van Verkeer en Waterstaat

Ir. M . Vis van Heem st AKZO N obel Engineering B.V.

With the issue of this third edition of the Yellow Book the Committee for the

Prevention of Disasters by Hazardou s Materials expects to promote t he general use

of standardised calculation methods of physical effects of the release of dangerous

materials (liquids and gases).

T he Hague, 1996

TH E COMMITEE FOR TH E PREVENTION OF

DISASTERS BY HAZARDOUS MATERIALS,

Drs. H .C.M . M iddelplaats, chairman


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V

Preface to the P GS 2 edition of the Yellow Book

Starting from June 1

st

2004, the Advisory Council on Dangerous

Substances (Adviesraad Gevaarlijke Stoffen - AGS) was installed by the Cabinet. At

the same time the Committee for the Prevention of Disasters (Commissie voor de

Preventie van Ram pen- C PR) was abolished.

CPR issued several publications, the so-called CPR-guidelines (CPR-richtlijnen),

that are often used in environmental permits, based on the En vironmental Protection

Law, and in the fields of of labou r safety, tran sport safety and fire safety.

The CPR-guidelines have been transformed into the Publication Series on

Dangerous Substances (P ublicatiereeks Gevaarlijke Stoffen P GS). T he aim of these

publications is generally the same as that of the CPR-guidelines. All CPR-guidelines

have been reviewed, taking into account the following questions:

1. Is there still a reason for existence for the guideline or can the guideline be

abolished;

2. Can the guideline be reintroduced without changes or does it need to be updated.

T he first print (1997) of the 3

rd

edition Yellow Book contained typographical errors

that occu rred du ring the conversion of the Yellow Book documen ts from one word

processing system to another. Most of these conversion errors occurred especially

with formulas, leading to erroneous and non-reproducible results when calculation

examples and formulas were recalculated.

This PGS 2 edition (2005) is a second print that has been thoroughly checked for

errors. Every chapter starts with a condensed summ ary of changes to give the user an

idea about what was changed and where it was changed.

Despite all effort, it might be possible that errors still persist. If this is the case, or if

you have any other remarks about the Yellow Book, please send a mail to:

[email protected].

Hard copies of this PGS-2 edition can be obtained from Frank van het Veld, TNO

Department of Ind ustrial & External Safety: [email protected], or fax +3 1 55 549

3390.

Also on behalf of my colleagues at the M inistries of T ransport, Social Affairs and of

the Interior,

T he State Secretary of Housing Spatial Planning and th e Environmen t (VROM ).

Drs. P.L.B.A van Geel

november 2005


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CPR 14E

Revision history of the Y ellow Book

Revision history

Date Release Comments

19 April 2005 3rd edition 2nd print, version 1 Please refer to the modification

paragrahs of all chapters.

25 July 2005 3rd edition 2nd print, version 2 The appendix of chapter 6 was

missing and has now been included.

Table 6.A.2 and Figure 6.A.11 were

not corresponding and has beencorrected.


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1.1

Chapter 1

General introduction

C .J.H . van den Bosch, R.A.P.M. Weterings


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1.2

Table of contents o f chapter 1

1.1 Introduction to chapter 1 .............................................................. 1.3

1.2 Educational objectives and target groups ....................................... 1.4

1.3 Contents of the Revised Yellow Book ............................................ 1.5

1.3.1 General remarks ................................................................. 1.5

1.3.2 Remarks on the individual chapters ..................................... 1.6

1.4 User instructions .......................................................................... 1.8

1.5 References.................................................................................... 1.9


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CPR 14E

Chapter 1 of the Y ellow Book

1.3

1.1 Introduction to chapter 1

For designers, manufacturers of industrial equipment, operators and

responsible authorities it is essential to have models available for assessing the

physical effects of accidental releases of hazardou s mat erials.

For this purpose th e hand book Methods for the calculation of physical effects of the

release of dangerous materials (liquids and gases), was issued by the Directorate

General of Labour in 1979.

In th e past decade the hand book has been widely recognised as an impor tant tool to

be used in safety and risk assessment stud ies to evaluate the risks of activities involving

hazardous materials. Because of its yellow cover, the handbook is world-wide known

as the Yellow Book.

T he Yellow Book, originat ing from 1979, was par tially revised in 1988. However, it

can be stated that the Yellow Book issued in 1988 was almost entirely based on

literature published before 1979.

T he current version of the Yellow Book results from an extensive study and

evaluation of recent literature on models for the calculation of physical effects of the

release of dangerous materials. T he C omm ittee for the Prevention of Disasters,

Subcom mittee Risk Evaluation started this project in June 1993 and it was completed

in March 1996.

This project was carried out by TNO Institute of Environmental Sciences, Energy

Research and Process Innovation, T NO Prins Maurits Laboratory and T NO Centre

for T echnology and Policy Stud ies.

T he project was supervised by a steering commitee with representatives from

governmental organisations and proces industries with the following members:

B.J.M. Ale, E.F. Blokker (chairman), R. Dauwe, E.A. van Kleef, Mrs. M.

Kru iskamp, R.O .M. van Loo, A.J. Muyselaar, A.W. Peters, K. P osthuma (secretary),

H.G. Roodbol, A.F.M. van der Staak, M. Vis van Heemst.

T he revision had the following three objectives:

1. to upd ate individual models from a scientific point of view, and to complete the

book with models that were lacking,

2. to describe the interfacing (coupling) of models,

3. to meet educational requirements.

T his general introdu ction starts with a description of the edu cational objectives

pursued by the Yellow Book. A general description of the target groups is envisioned

(in section 1.2). T he differences between th is edition and the p revious edition are

elucidated in section 1.3. Finally (in section 1.4), guidance will be given to the reader

regarding how to use the Yellow Book.


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1.4

1.2 Educational objectives and targe t groups

In the first phase of the process of developing this update of the Yellow

Book, an educational framework was formulated [Weterings, 1993] and a set of

educational objectives was defined. Studying the Yellow Book the reader may expect

to :

a. gain knowledge of the phenomena relevant to estimating the physical effects of the

release of hazardous materials,

b. gain knowledge of the mod els that have been developed to describe these

phenomena,

c. gain un derstanding of the general principles of the selection of these models, and

of the conditions und er which these models can be applied,

d. gain und erstanding of the procedure according to which the selected modelsshould be app lied,

e. be able to apply the selected models in practical situations, and to interface them

adequately to related models for estimating physical effects of hazardous releases,

according to more complex release scenarios.

T he Yellow Book has been written in such a manner as to m eet the requirements of:

chemical industry,

technical consultancy bureaus,

engineering contractors,

authorities and government services (national and regional level),

institutes for advanced research and education.

It should be kept in m ind that these target groups will use the models for estimating

physical effects of hazardous releases for different purposes. Table 1.1 presents some

of the purposes for which specialists from industry, government agencies or

consultancy may use the presented models. T he number of stars gives some

indication of the frequency in which the m odels are used in p ractice.

Table 1.1 Selected target groups and purposes in estimating physical effects

Purpose Target groups

Companies Authorities Consultants

Design of installations *** * **

Quantified risk assessment *** ** ***

Workers safety * *

Emergency planning ** ** *


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CPR 14E


1.5

1. 3 C on te nts of th e Re vis ed Ye llo w B oo k

1. 3. 1 General rem arks

In the past decade, considerable progress has been made in modelling

physical effects resulting from acciden tal releases of a hazardous material.

T he current revision has been based on available data in the open literature and

known state-of-the-art m odels, and maintains more or less the same structure as the

former version:

T he strongly increased availability of powerful (personal) computers has caused a

shift in the application of analytical models and physical correlations towards complexcomputerised numerical models. We aimed to collect models that combine a good

scientific performance with ease of application in practice.

It appears that the optimal combination of models varies for different classes of

physical effect models; some models are simple correlations, many models consist of

a straight forward numerical scheme, but few models are unavoidably complex as the

related physical phenomena have a comp lex nature.

T he selected models are described in a way to make computerisation b y the reader

possible in p rinciple, yet p rices of available software packages are relatively low.

An inventory of the applicable models available in the field of safety and hazard

assessment studies has shown the white spots left in this area.

Guidelines on how to deal with white spots in the revised Yellow Book have beenbased on engineering judgement , which may lead to simple rules of the thumb.

Chapter Author

1. G eneral Introduction C .J.H . van den Bosch and

R.A.P.M. Weterings

2. Outflow and Spray Release C.J.H. van den Bosch and

N.J. Duijm

3. Pool Evaporation C.J.H . van den Bosch

4. Vapour Cloud Dispersion N.J. Duijm and E. Bakkum

5. Vapour Cloud Explosions W.P.M. Mercx andA.C. van den Berg

6. Heat Fluxes from Fires W.J.F.M. Engelhard

7. Ruptures of Vessels R.M .M . van Wees and

J.C.A.M. van Doormaal

8. Interfacing of M odels C .J.H . van den Bosch


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1.6

Although the Yellow Book focuses on liquids and gases, under certain conditionssome models may be applied for solids. In particular, atm ospheric dispersion m odels

may be used to estimate concentrations of non-d epositing dust in the atm osphere, or

concentrations of volatile reaction products of burning solids.

1.3.2 Remarks on the individual chapters

Below, the major improvements and differences in this version of the

Yellow Book in relation to the former edition are outlined.

In chapter 2 Outflow and Spray Release a rather fast model for two-phase flow inpipes is given as well as several models about non-stationary outflow from long pipe

lines. Much attention is given to the dynamic behaviour of the content of vessels due

to the release of material.

An adequate model for spray release is presented, explaining amongst others why

light gases such as ammonia can behave like a heavy gas under certain

circumstances.

In chapter 3 Pool Evaporation a model for the evaporation of a (non-)spreading

boiling and non-boiling liquid pool on land or on water is described. This model

overcomes many numerical boundary problems encountered in the past, but is also

quite complex. In addition a model for the evaporation of volatile solved chemicals in

water is given.

Chapter 4 Vapour Cloud Dispersion reflects the m ajor scientific progress that has

been m ade on modelling heavy gas dispersion. T he plume rise mod el has been

extended for heavy gases. Also a new description is given for the atmospheric

boundary layer stability.

In chapter 5 Vapour Cloud Explosions a new method for the prediction of blasts

resulting from confined vapour cloud explosions is described. T his so-called Multi-

Energy-Method is an improvement to earlier methods. Although not fully developed

yet, it is able to incorporate results of future experiments on vapour cloud explosions.

In chapter 6 Heat Fluxes from Fires a new model for gas flares and a model forconfined p ool fires on land and water are included .

In chapter 7 Ruptures of Vessels models are described for several different types of

vessel ruptu res leading to b last and fragmentation. Although these models are mu ch

more adequate than previous models, they are not yet able to render very accurate

predictions.

In chapter 8 Interfacing of Models atten tion is given to the interfacing of the physical

effect models described in the previous chapters. Often (subsequent) physical effects

are involved in between the release of hazardous material and the actual impact on

people and properties causing damage. So, physical effect models may have to be

coupled, meaning that their results, i.e. the predictions of these models (outputdata), have to be adapted and transferred to serve as input to other subsequent


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CPR 14E


1.7

models. The procedure of adaptation and transfer of data is usually addressed byinterfacing.

T he remainder of this chapt er deals with the physical effects of BLE VEs.

A BLEVE (Boiling Liquid Expanding Vapour Explosion) causes several physical

effects: heat radiation, pressure waves and fragmentation, that may cause damage.

T hese phenomena will be treated in different chapters. In order to present an overall

picture of the BLEVE an integral calculation example is given in chapter 8.


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1.8

1.4 User instructions

The educational design provides a framework according to which this

version of the Yellow Book has been structured. This framework defines the topics to

be considered in separate sections, and reflects a causal chain of effects to be a logical

argument in determining the sequence in which these topics should b e addressed. As

a result the Yellow Book starts with a section on outflow and spray release (chapter

2), then addresses evaporation (chapter 3) and dispersion (chapter 4), before

addressing several other specific aspects, such as vapour cloud explosion (chapter 5),

heat load (chapter 6) and the rupture of vessels (chapter 7). Finally a section on

interfacing related models (chapter 8) illustrates how to proceed in applying a

sequence of models in estimating physical effects, according to a few selected

scenarios.

Using the Yellow Book, it is helpful to keep in mind that all chapters are structured

in a similar m anner. Each of the chapters 2 to 7 contains the following sections:

section 1 provides an introduction

and p ositions the chapter in relation to other

chapters,

section 2 provides a general introduction and defines relevant phenom ena

,

section 3 gives a general overview

of existing (categories) of models for the

phenomena addressed,

section 4 describes criteria

according to which a limited number of models has

been selected,

section 5 provides a detailed description of the selected models

: the general

principles and assumptions on which they have been based, the procedureaccording to which these models should be applied as well as some considerations

on t heir potential and limitations in practice,

section 6 illustrates the practical application of the selected models by means of

calculation exam ples

,

section 7 addresses relevant issues in relation to interfacing

the selected models

with other models,

section 8 provides some discussion

on t he state-of-the art in the field addressed,

which is relevant in view of assumptions and limitations of the selected models.

In conclusion, for background information the reader is referred to the sections 1 to

4 of each chapter. However, if the reader has already mastered the general principles

of the selected models, it is advised to concentrate on the sections 5 and 6 and ifnecessary also sections 7 and 8 in which a detailed description is given of how to use

the most relevant models for estimating the physical effects of hazardous releases.


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CPR 14E


1.5 References

YellowBook (1988),

Methods for the calculation of physical effects of the release of dangerous materials

(liquids and gases) 2

nd

ed.,1988), published by Directorate General of Labour;

English version, 1992).

Weterings (1993) ,

R.A.P.M. Weterings, T he revised Yellow Book - educational concept,

TNO Centre for Technology and Policy Studies (STB), Apeldoorn, October 1993.

pgs2-1997 methods for the calculation of physical effects chapter 1 general introiduction

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