서울대학교 화학공정신기술연구소

공정시스템 및 안전연구센터

김 구 회

화학공정의 사고 시나리오합성 시스템

Automatic Synthesis of Robust Accident Scenarios for Chemical Processes

Hazard Analysis

HazardIdentification

AccidentProbability

AccidentConsequence

RISK MANAGEMENT

정성적 추론 정량적 추론

공정내 사고로 인한손실 발생

위험영향평가기술

가상사고시나리오사용자의 주관에 의존평가결과의 다양성한계

사고시나리오합성

공정요소 분석장치거동 분석물질특성 고려사고형태 추론

• HAZOP Study

• FMEA

• What-If analysis

• PHA

• FTA

• ETA

• The starting point of analysis

• The direction of inference

• The scope of analysis

전통적인 위험성 평가 방법

• Time consuming

• Labor intensive

• Requiring extensive and multidisciplinary knowledge

• The quality of analysis is dependent on the analyst’ s ability

INFERENCE STRUCTURE using Rule-based method

기존 위험성 평가 방법의 단점

가상 사고 시나리오란?

정성적 안전성평가방법

미국에서 처음 WCS(Worst Case Scenario)의 개념 도입

위험영향평가시스템의 입력값으로 가상사고 시나리오에 따라 결과의 다양성 존재

체계적 방법에 따른 시나리오 추론

공정상태 분석 및 및 발생 강도 고려

제안된 가상사고 시나리오 추론구조

GLOBAL INFERENCE ENGINE

AccidentScenario

KnowledgeBase

USER

Equipment ScreeningAlgorithm

Equipment BehaviorAnalysis Algorithm

Accident ScenarioReasoning Algorithm

Equipment PropertyKnowledge-Base

Material PropertyKnowledge-Base

Process unitKnowledge-Base

Equipment Property KB

- NAME : Feed line valve

- UNIT ID :

- CONNECTED FROM

- CONNECTED TO :

- SAFETY UNITS : PressureTemperatureFlow rate

- MATERIALS :

N/AN/ACONTROLLER BY VALVE1

PIPE 4

PIPE 3

VALVE

Toluene

- FLOW RATE : 5 kg/s

- TEMPERATURE : 298 K

- PRESSURE : 2 kg/cm2...

Material knowledge base

사용된 물질 특성

NFPA rating(Nf, Nr, Nh)

Heat of combustion

Flash point

Boiling point

MF(NFPA material factor)연소열, flash point, boiling point 고려

Material Property KB

NFPA code

• API 750• Dow & Mond Index....

• Nh : Health Hazard Rating• Nf : Flammable Hazard Rating• Nr : Reactivity Hazard Rating

HAZARD INDEX

AMMONIA

Nr = 0Nh = 3Nf = 1

HC = 8,000FP = gasBP = -28

EO

Nr = 3Nh = 3Nf = 4

HC = 11,700FP = -4BP = 51

C3Nr = 0Nh = 1Nf = 4

HC = 19,900FP = gasBP = -44

HC(Heat of Combustion, Btu/lb)FP(Flash Point, ℉)BP(Boiling Point, ℉)

1

3 2

W

Flammability (Red)

4:Extremely flammable3:Highly flammability2:Flammability1:Low flammability0:Not flammable

Health Hazard (Blue)

4:Extremely hazardous3:Highly hazardous2:Hazardous1:Slightly hazardous0:Not hazardous

Reactivity hazard (Yellow)

4:Severe explosion risk3:Explosion risk2:Potentially explosive1:Not violently reactive0:Normal stability

Other hazard (if any)

W:Do not use waterOXY:Oxidizing♦:Radiation hazard

Nf

Nr

0 1 2 3 4

0 1 1 2 3 4

1 1 1 2 3 4

2 2 2 4 6 9

3 3 3 6 9 12

4 4 4 8 12 16

복합 특성의 고려(Multi-property matrix)

화학공정에서의 단위공정 분류

CHEMICAL/ENERGYPLANT

Oxidation, Electrolysis, NitrationEsterification, Aminolysis, Sulfonation,

Alkylation, Polymerization

이송,분배공정

분리, 정제공정냉각, 소각, 열처리,

열가공, 배가스, 폐수,폐기물 처리공정

원료,부산물, 및최종생산물의 저장공정

반응시스템

공급시스템

분리시스템 유틸리티시스템

저장시스템

Process Unit KB-1

Chemical Process Unit Classification

Process Unit

-Feed System, Reaction System,Production System, Storage System,

Utility System

Safety Unit

-Mitigative Safeguard-Preventive Safeguard

Topography

Meteorological data

Characteristic of surrounding area

Process Unit KB-2

Unit 1

materials

Propane(G)

Butane(G)

Water

Air

Composition

Stripper

Air fan

Stripper pump

Number ofAnalysis node

4

Unit 2

materials

Propane(L)

Propane(G)

Butane(L)

Butane(G)

Composition

Dry tank(3)

Heater(2)

Pump(7)

Cavern

Number ofAnalysis node

12

Unit 3

materials

Methanol

Odorant

Nitrogen

Composition

Storage tank

Pump(2)

Number ofAnalysis node

6

Unit 4

materials

Propane(L)

Butane(L)

Composition

Unloading arm

Pump(2)

Number ofAnalysis node

4

Characteristics of Surrounding AreaMeteorological Characteristics

가상사고 시나리오 추론단계

Macro Decomposition(Unit function and topography analysis)

Micro Decomposition(Equipment screening

with equipment knowledge base)

Equipment Behavior Analysis(Root cause and effect reasoning)

Process Unit Selection

Process Equipment Selection

Accident Reasoning(EFaCRA and material knowledge base)

Accident Scenarios at Given Mode

Accident Scenarios Selection

Effect Analysis Emergency Planning And Safety Device

Secondary Equipment

Macro Decomposition Algorithm

시나리오 추론과정의 첫번째 단계 주요 기능시스템의 구분과 정의

Feed system, Reaction system, Production system, Storage system, Utility system

기후적 특성 고려 평균 풍향 및 풍속

Topography 인근지역의 주거비, 지리적 환경

Material Highly toxic, flammable material

Macro Decomposition Algorithm

UnitDecomposition

Detailed Analysis

Macro Decomposition Algorithm

Unit 1Storage unit

Unit 2Reaction unit

Unit 3Reaction unit

Unit 4Storage unit

Unit 5Utility unit

Unit 6Utility unit

Wind Direction

CommercialArea

ResidentArea

Wind Direction

Equipment Screening Algorithm

대상공정에 대한 세부요소 분석 물질의 특성

NFPA rating 3 이상

운전조건 초고온, 초저온상태

액화가스, 압축가스, 가연성물질에 따라 분류

유량 공정에 따른 상대적 유량

안전장치 Preventive safety device

장치의 연수

사고사례

Screening 기준

Equipment Screening Engine(Rule-Based)

Chemical PropertyNFPA rating

Combustion of HeatFlash Point

Operating ConditionPressure

TemperatureFlow Rate

Age(averaging age)

Safety DevicePreventive DeviceMitigative Device)

Accident History Repaired HistoryFailure Rate

(yr-1)

REPAIRED HISTORY

ACCIDENT HISTORY

FAILURE RATE

AGE

SAFETY DEVICE

OPERATING CONDITION

FLOW RATE

MATERIAL PROPERTY

Sequential Reasoning

Consequence Analysis

Probability Analysis

기준에 따른 절대값

상대적 지침

Preventive Safeguard

Failure Probability

최종 우선순위를 위한 참고지침

Screening guideword의 우선순위에

대한 기준

HIRA(Hazard Identification and Ranking) Khan & Abbasi (1998)

Relative ranking method

Two Indices: Fire and Explosion Damage Index (FEDI)

Toxic Damage Index (TDI)

It provides quantitative scores; Easy interpretation of results

Comparison of hazards

Relative Sensitivity Analysis

공정변수들이 시나리오 결과에 미치는 영향의 정도를비교

무차원군으로 표현

±10% change Heat of combustion (i.e., material itself)

Operating pressure

Operating temperature

Quantity (or flow rate)

xy

xx

yy

S yx ln

ln∂∂=∂

∂=

Relative Sensitivity Analysis - Results

Analysis Results (김, 2000)

물질의 종류/양(유속)이 공정 온도/압력보다 더 민감한 변수

±10% ChangesRelative

Sensitivity

Heat of combustion 0.33 (avg.)

Operating pressure under 10E-4

Operating temperature under 10E-4

Quantity (or flow rate): 0.33 (avg.)

Relative Sensitivity Analysis - Results

0

0.5

Relative Sensitivity

Relative Sensitivity Analysis Results

Hc

Temp.

Press.

Quan.

Equipment Screening Algorithm

OperatingCondition

Flow-rate

SafetyDevice

Age

AccidentHistory

MaterialProperty

액화가스 : 2 kg/cm2 이상압축가스 : 10kg/cm2 이상가연성 액체 : 상온 상압 이상

유량 5 kg/s 이상

Interlock system이나 비상밸브의장착 여부

평균수명 이상 되는 장치 여부

유사장치나 공정의 사고 유무

NFPA rating 3 이상(Nh Nf Nr)

A B C D E F G H DESCRIPTIONIGuideword

Component

Equipment Behavior Analysis-1(Equipment Failure and Cause Reasoning Algorithm)

Qualitative analysis 장치의 fail 여부에 따른 분석(Forward,

Backward)

각 장치별로 작성

각 장치의 이상원인과 결과 추론

Property of materials Material의 특성에 따른 등급 부여

Toxicity, Flammability

NFPA rating

Equipment Behavior Analysis-2

Heat Exchanger,High Pressure

Leak Rupture

Fouling

Valve

Open Closed

Rupture Leak

Pump

On Off

Seal Leak/RuptureCasing Leak/Rupture

Equipment Failure and Cause Reasoning Algorithm(EFaCRA)

Failure Mode

Cause Reasoning(Backward) Effect Reasoning(Forward)

Effect Propagation(Internal/External)

Ultimate Effect(Possible Accidents)

Effect Calculation

Preventive Measure/Emergency Plan

Cause analysis for Failure mode(Internal/External)

Root Cause

Safeguard

Equipment Failure and Cause Reasoning Algorithm(EFaCRA)

Fail Closed(No flow)

Internal

ExternalExternal

InternalMotor failure

Malfunction

Indicator error

Electricityshut-down

Sedimentation

Internalhigh pressure

Rapid eddy

No flowExternal stream

Back-flow

Inlet highflow/pressure

Cause Effect

Corrosion

Abrasion

Mechanicalerror

Sensor failure

Abrupt reaction

Impurity upstream

Valve breakage

Downstreamfailure

Downstreamequipmentbreakage

Root Cause Ultimate Effect

Accident Reasoning Algorithm

ACCIDENTANALYSIS

ALGORITHM: RULE

Fire...

Personnel Injury

Explosion

...

Equipment Damage

Toxic Material Release

Accident ScenariosKnowledge Base

Material PropertyKnowledge Base

MaterialHazardIndex

UltimateEffect

EFaCRA

NFPA Rating

Case Study-1

가연성액체 저장 설비 및 loading 설비

Tank truck으로 부터 가연성액체를padding 상태로 T-1에 저장

Valve 7개, 저장탱크 1개, 펌프 1개

PICA-1

TIA-1

LIA-1

PI-1

FICA-1

To the nextprocess

FV-1V-4

P-1

V-31”

4”

V-1

1”

From tanktruck

RV-1

V-6

PV-2

1”

1” PV-1

V-7

To atmosphereNitrogen To flare

Flammable Storage TankT-1

V-2

V-5

Equipment Screening Algorithm

OperatingCondition

Flow-rate

SafetyDevice

Age

AccidentHistory

MaterialProperty

액화가스 : 2 kg/cm2 이상압축가스 : 10kg/cm2 이상가연성액체 : 상압 이상

유량 5 kg/s 이상

Interlock system이나 비상밸브의장착 여부

평균수명 이상 되는 장치 여부

유사장치나 공정의 사고 유무

NFPA rating 3 이상(Nh Nf Nr)

V-1 V-3 V-4 V-5 V-6 V-7 PV-1 PV-2 DESCRIPTIONFV-1Guideword

ComponentV-2 P-1

Equipment Behavior Analysis Algorithm

Equip. Mode

Cause

(Root Cause) EffectUltimate

EffectMat.

Relative Risk

Ranking

Valve

(V-5)

on the feed line

Fail open

Motor failure

Malfunction

Sensor failure

Electric shut-down

Excess flow of flammable liquid to the storage tank

High level in the storage tank

May cause tank rupture

due to overpressure

Flam-mable liquid

A

(Fire)

Equip. ModeCause

(Root Cause)Effect

Ultimate

EffectMat.

Relative Risk

Ranking

Valve

(V-5)

on the feed line

Fail

closed

Motor failure

Malfunction

Sensor failure

Electric

shut-down

Sedimentation

Impurity upstream

No flow of flammable liquid to

the reactor

Overpressure of inlet of the pump

P-1

Overpressure of the tank truck

Internal high pressure

back-flow to

the Cavern

May cause tank rupture

due to overpressure

May cause valve breakage

Flammable liquid

Flammable liquid

A

(Equip.damage

/fire)

A (Equip.damage

/fire)

Equip. ModeCause

(Root Cause)Effect

Ultimate

EffectMat.

Relative Risk

Ranking

Valve

(V-5)

on the feed line

Leak Corrosion

Abrasion

Outer impact

Small release of flammable liquid to

the surrounding area

Release of flammable liquid

Flammable liquid

B

(Fire)

Equip. ModeCause

(Root Cause)Effect

Ultimate

EffectMat.

Relative Risk

Ranking

Valve

(V-5)

on the feed line

Rup-

Ture

Corrosion

Abrasion

Outer impact

Large release of flammable liquid to

the surrounding

Area

Release of flammable liquid

Flammable liquid

A

(Fire)

Case Study-2

C3 이송, 저장, 공급시설

해양의 선박으로부터 공급 받아 지하동굴형저장시설(cavern)에 저장한 후, 공급

Cavern, dryer 5개, stripper 2개, odorant storage tank, inhibitor storage tank, heater 3개, pump 26개, valve 67개 등으로구성

C3/C4Storage Tank

Inhibitor Drum

Odorant Drum

C3/C4 Cavern

Dryer

N2 Storage TankAir Stripper

C3/C4 Heater

Boosting Pump

Unloading Arm

Loading Arm Vent Stack

Air

Stripper pump

Methanol Injection Pump

Odorant Injection Pump

C3/C4 transfer Pump

V-1

V-2

V-4

V-3

V-5

V-6

V-7

V-8

V-9

V-10

V-11

V-12V-13

P-1

P-2

P-3

P-4P-5

P-6

H-1

A

B CD E

F

G

H

I

J

K

L

M

N

C3/C4

Control Room

Utility Area

EducationCenter

OfficeDining &

Rest Room

Power FacilityGate

Unloading AreaSEA

SEA

CavernArea

Residential Area

Air Comp.

Stream

NO.Fluid

Temperature

( C)

Pressure

(kg/cm2G)

Flow Rate

m3/h

(ton/h)

Density

(kg/m3)

A C3 Liquid -45 5.0 2000 585

B C3 Liquid -45 3.4 2000 585

C C3 Liquid -45 9.0 2000 585

D C3 Liquid -45 8.9 2000 585

E C3 Liquid 2 7.6 2000 527

F C3 Liquid 8.8 16.7 1568 517

G C3 Liquid 8.8 16.4 608 517

H C3 Liquid 8.8 14.4 608 517

I C3 Gas 5 6.1 - -

JWater

/C3 Gas7.1 8.3 250 1010

K Water 7.2 0 350 1010

L Nitrogen AMB. 4.0 - -

M MeOH AMB. 24 4.5 0.79

N ROH AMB. 24 0.3 0.84

OperatingCondition

Flow-rate

SafetyDevice

Age

AccidentHistory

MaterialProperty

액화가스 : 2 kg/cm2 이상압축가스 : 10kg/cm2 이상가연성액체 : 상압 이상

유량 600 m3/H 이상

Interlock system이나 비상밸브의장착 여부

평균수명 이상 되는 장치 여부

유사장치나 공정의 사고 유무

NFPA rating 3 이상(Nh Nf Nr)

H1 P2 P3 P4 P5 P6 V1 V2 DESCRIPTIONV3Guideword

ComponentP1 V4 V5 V7 V8 V9 V10 V11 V12 V13V6

Equip. ModeCause

(Root Cause)

Effect Ultimate

EffectMat.

Relative Risk

Ranking

Valve (V-5)

on the line to

the dryer

Fail

open

Motor failure

Malfunction

Sensor failure

Low hydraulic

pressure

Electric

shut-down

Excess flow of Flammable liquid

to the dryer

High level in the dryer

Overpressure in the dryer

May cause

tank rupture

due to over-pressure

C3

(L.G)

A

(Fire/Ex-plosion)

Equip. ModeCause

(Root Cause)

Effect Ultimate

EffectMat.

Relative Risk

Ranking

Valve (V-5)

on the line to the

dryer

Fail

closed

Motor failure

Malfunction

Sensor failure

Low hydraulic

pressure

Electric

shut-down

No flow of C3 to the dryer tank

Low level in the dry and dry tank

Internal high pressure

Rapid eddy

Back-flow to cavern

High pressure of outlet pump in the

cavern

Inlet pump fail due to high pressure

May cause

tank rupture

in the cavern

May cause

valve

breakage

C3

(L.G)

C3

(L.G)

C

(Pump

Damage)

A

(Fire.Expl-osion)

Equip. ModeCause

(Root Cause)Effect

Ultimate

EffectMat.

Relative Risk

Ranking

Valve (V-5)

on the line to

the dryer

Leak Corrosion

Abrasion

Outer impact

Small release

Of C3 to the surrounding

area

Release of C3 C3

(L.G)

B

(Fire/Ex-plosion)

Equip. ModeCause

(Root Cause)Effect

Ultimate

EffectMat.

Relative Risk

Ranking

Valve (V-5)

on the line to

the dryer

Rup-

ture

Corrosion

Abrasion

Outer impact

Large release

of C3 to the

surrounding

area

Release of C3 C3

(L.G)

A

(Fire/Ex-plosion)

Equip. Mode

Cause

(Root Cause) EffectUltimate

EffectMat.

Relative Risk

Ranking

Heat

exchanger(H-1) on the feed

line to

the

cavern

Leak

(tube

To

shell)

Corrosion

Abrasion

Outer impact

Over flow rate

or high

pressure of

inlet line

Small release

of C3 to the

shell side

Less flow of C3 to the cavern

High pressure

of water stream

Low pressure of inlet stream to the

cavern

Release of C3 C3

(L.G)

B

(Fire/Ex-plosion)

Equip. ModeCause

(Root Cause)Effect

Ultimate

EffectMat.

Relative Risk

Ranking

Heat

exchanger(H-1) on the feed

line to

the cavern

Rup-

ture

(tube

To

shell)

Corrosion

Abrasion

Outer impact

Over flow rate

or high

pressure of

inlet line

Large release

of C3 to the

shell side

No flow of C3 to the cavern

High pressure

of water stream

May cause

shell side

rupture due

to overpressure

Heat exchange

damage

C3A

(Fire/Ex-plosion)

Equip. ModeCause

(Root Cause)Effect

Ultimate

EffectMat.

Relative Risk

Ranking

Heat

exchanger(H-1) on the feed

line to

the cavern

Leak

(tube

To

Exter-nall)

Corrosion

Abrasion

Outer impact

Small release

of water to the

surrounding

area

Less flow of

water in the

shell side

Lowering

function of heat exchanger

Heat-

exchanger

damage

Water -

Equip. ModeCause

(Root Cause)Effect

Ultimate

EffectMat.

Relative Risk

Ranking

Heat

exchanger(H-1) on the feed

line to

the cavern

Rup-

ture

(tube

To

Exter-nal)

Corrosion

Abrasion

Outer impact

Large release

of water to the

tube area

No flow of

water in the

shell side

Malfunction of

exchanger

Heat-

exchanger

damage

Water-

Equip. ModeCause

(Root Cause)

Effect Ultimate

EffectMat.

Relative Risk

Ranking

Heat

exchanger(H-1) on the feed

line to

the cavern

Plugged

(tube

side)

Sedimentation

Abrupt reaction

Impurity

upstream

Outlet valve fail

No flow of C3

to the cavern

Internal high

pressure

Rapid eddy

Back-flow to the pump (P-1)

High pressure

of inlet pump

Inlet pump fail

due to high pressure

May cause

tube rupture

due to

overpressure

Pump and heat

exchanger

damage

C3 -

Equip. ModeCause

(Root Cause)Effect

Ultimate

EffectMat.

Relative Risk

Ranking

Heat

exchanger(H-1) on the feed

line to

the cavern

Plugged

(shell

side

Abrupt reaction

Impurity in

shell side

Lowering

function of heat exchanger

Heat-

exchanger

damage

- -

결론 및 제안사항

Fault tree analysis와 effect analysis와의 연계 Accident probability와 accident consequence analysis로의

확장

AccidentProbability

HazardIdentification

AccidentConsequence

정량적 추론 정량적 추론

Hazard Analysis

ARA 분석결과의 정량화 가능성

Ultimate effect와 material property의 정량화

Ultimate effect의 고려 Release of material

Equipment failure

Downstream fail

Upstream fail

각각의 ultimate effect에 대한 penalty 크기에 따른 penalty(1-5)

Material property에 대한 penalty 복합 특성 등급 사용(0-16)

Release of material(5)

Equipment fail(3)

Downstream fail(2)

Upstream fail(2)

C3(4)

EO(12)

Am(3)

C3(4)

Magnitude ofPotential Damage

And Possible Accident

물질의 복합특성Ultimate Effect

Material Property(복합물질 등급 또는 MF)

Release of materialEquipment breakage

Upstream failDownstream fail에 대한

PENALTY

발생가능 사고유형 및 등급Fire

ExplosionToxic release

Equipment damage

이상원인에 대한상황 및 근본 이상

원인

이상으로 발생 가능한 상황

ConsequenceAnalysis

Reports

Data 관리 DataBase

실시간 공정 조업 Real-Time DB, PFD

공정 설계 GIS, PFD

공정 관리 Emergency Planning