RISK-BASED DESIGN TOOLS FOR PROCESS FACILITIES · 2016. 10. 18. · Dynamic HAZID Model • Step 1:...

CENTRE FOR RISK, INTEGRITY AND SAFETY ENGINEERING WWW.MUN.CA/ENGINEERING/RESEARCH/CRISE

RISK-BASED DESIGN TOOLS FOR

PROCESS FACILITIES

Peiwei Xin

M.Eng, Oil and Gas Engineering

Memorial University of Newfoundland


Content

Risk-Based Design

Risk-Based Design Tools

• Hazard Identification Tool

• Layout Optimization Technique

2


Risk-Based Design

What is risk-based design?

• Incorporate risk-analysis

• Complementary approach to traditional design

• Cost-effective

• The ultimate goal is to make the total risk meet the

following criterion:

Rdesign ≤ Racceptable

• Design for safety

3


Risk-Based Design

What does a risk-based design process include?

4


Risk-Based Design

Research Objective

5


Risk-Based Design

Research Objective

6


Dynamic Hazard Identification and Scenario

Mapping Using Bayesian Network

Part I


Dynamic Hazard Identification

Hazard identification

• Hazard identification and risk assessment

• Answers what can go wrong

• Methods of hazard identification

• Dynamic hazard identification

Hazard and hazard scenarios

• Hazard scenario can be a single event or combination of

events

• Hazard scenario depicts the evolution of hazards

• Hazard evolution is linear progression

8


Dynamic Hazard Identification

Bayesian Network (BN)

• Graphic modeling tool

• Consisted of a qualitative part and a quantitative part

• Mapping interdependence among random variables

Why Bayesian?

• Types of hazards and their causes can be represented by propositional

variables with multiple states in a BN;

• Directed edges help to encode causal relations in the evolution of

hazards

• Deterministic and probabilistic evidence represent situations in real

practice and effectively solve problems brought by uncertainties

• Assign the most credible hazards a probability ranking

9


Methodology of Constructing

Dynamic HAZID Model

• Step 1: Create hazard scenarios

• Step 2: Identifying nodes

• Step 3: Classifying nodes

• Step 4: Mapping causal relations among nodes

• Step 5: Assigning conditional probability tables (CPTs)

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Create hazard scenarios

11


Generic Dynamic HAZID Model

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Model Validation

Study 1: Chevron Richmond Vapour Fire

Source:http://www.csb.gov/chevron-refinery-fire/

Study 2: Vapour cloud explosion Source:http://www.csb.gov/cai-/-arnel-chemical-plant-explosion/

Study 3: Ammonia toxic release Source:http://www.csb.gov/millard-refrigerated-services-ammonia-release/

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http://www.csb.gov/chevron-refinery-fire/







http://www.csb.gov/cai-/-arnel-chemical-plant-explosion/












http://www.csb.gov/millard-refrigerated-services-ammonia-release/











Model Validation – Study 1

Simulation Results (Vapor Fire, California, 2012)

Carbon Steel Pipe

(Light Gas Oil)

Sulfidation

Corrosion Pipe Rupture

Vapour

Release

Vapour Cloud

Formation Vapor Fire

Ignited

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Model Validation – Study 1 Simulation Results (Vapor Fire, California, 2012)

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Simulation Results (VCE, Danvers, 2006)

Human Error Steam Valve

Open

Flammable Liquid

Overheating

Vapour

Release

Vapour Cloud

Formation VCE

Ignited

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Model Validation – Study 2 Simulation Results (VCE, Danvers, 2006)

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Simulation Results (Toxic Release, Alabama,2010)

Refrigeration Coil Hydraulic

Shock Rupture

Toxic Ammonia

Release Toxicity

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Model Validation – Study 3 Simulation Results (Toxic Release, Alabama,2010)

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Sensitivity Analysis

Simulation Results

20


Sensitivity Analysis – Fire & Explosion

21


Sensitivity Analysis – Pressure

22


23

Sensitivity Analysis – Pressure


24

Sensitivity Analysis – Material

Strength and Overflow


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Sensitivity Analysis – Material

Strength and Overflow


Sensitivity Analysis -Conclusion

• Confinement has the largest influence on the occurrence

of a fire or explosion, and a high confinement condition

more likely results in an explosion scenario.

• Pressure influences the type of fire to a great extent.

• Material strength and an overflow of equipment influence

the probability of explosion significantly, with the material

strength having larger influence.

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Layout Optimization of A Floating Liquefied

Natural Gas Facility Using Inherent Safety

Principles

Part II


Content

Introduction of Floating LNG facility

Floating LNG topside deck design

Inherent safety method

Layout Optimization

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Floating LNG Facility

What are Floating LNG facilities ?

• Floating, production, storage, offloading (FPSO)

What are the advantages?

• Long distance transportation & multi-location

• Inaccessible area Accessible

• Solution to marginal areas

• Environmental advantages

Source: http://theenergycollective.com/celinerottier/189491/will-

floating-lng-revolutionise-natural-gas-industry

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FLNG Topside Deck Design

Importance of Layout

• Decide arrangement of Area and Equipment

• Affect complexity of Piping System

• Access of Plant & Emergency Response Plan

• Routes of Hazard Propagation

Topside Deck Design

• LNG Process Selection

• Process Area Design

• FLNG Topside Deck Design

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Liquefaction Process

Dual Mixed Refrigerant Liquefaction Process

• Adopted by Shell and Sakahalin Projects

• Dual Mixed Refrigerant Cycles

• Pre-mixed refri-cycle (PMR) cools natural gas to -30˚

• Mixed refri-cycle (MR) cools natural gas to -160˚

• High Efficiency &Large Capacity

31


Liquefaction Process Dual Mixed Refrigerant Cycle:

32


Liquefaction Process Dual Mixed Refrigerant Cycle:

33


FLNG Topside Deck Design Process Area Design:

• What if add storage area, living quarter, water treatment, and

control room?

34


FLNG Topside Deck Design Topside Layout:

35


Layout Evaluation Method

Inherent Safety Method

• Inherently eliminate and mitigate hazards

• Inherent guidewords of layout assessment

• Attenuation

• Simplification

• Limitation

• Index-based approach (Tugnoli, Khan, &Amyotte, 2008; Khan & Amyotte, 2004& 2005)

• Domino Hazard Index

• Integrated Inherent Safety Index (I2SI)

• Cost index

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Layout Evaluation Method

Layout Evaluation Calculation Method:

References: Tugnoli, A., Khan, F., Amyotte, P., & Cozzani, V., 2008, “Safety Assessment in Plant Layout Design Using Indexing Approach: Implementing Inherent

Safety Perspective: Part 1–Guideword Applicability and Method Description,” Journal of hazardous materials, 160(1), pp. 100-109.

Tugnoli, A., Khan, F., Amyotte, P., & Cozzani, V., 2008, “Safety Assessment in Plant Layout Design Using Indexing Approach: Implementing Inherent Safety

Perspective: Part 2–Domino Hazard Index and Case Study,” 160(1), pp. 110-121.

37


Layout Optimization

Comparison of Domino Hazard Index (DHI):

Comparison Results

• Safety measures can effectively prevent or mitigate hazard escalation.

• Less likely for separate modules to suffer hazard escalation (Domino

hazard).

38


Layout Optimization

Comparison of Integrated Inherent Safety Index (I2SI):

No. Unit DI PHCI HCI ISI I2SI Base Option ISI I2SI Option 2 ISI I2SI Option 3

1 Absorber 35.7 56 22 5.00 0.36 12.25 0.87 12.24 0.87

2 Distiller 35.7 56 22 5.00 0.36 12.25 0.87 12.24 0.87

3 Cooler 26.5 46 22 5.00 0.39 23.43 1.85 23.43 1.85

4 Common Header 26.5 30 22 5.00 0.26 12.25 0.63 12.24 0.63

5 PMR Suction Drum1 26.5 40 22 5.00 0.34 1.89 0.13 1.73 0.12

6 PMR Suction Drum2 26.5 50 22 5.00 0.43 1.89 0.16 1.73 0.15

7 PMR Compressor1 34.7 56 26 5.00 0.31 7.15 0.44 21.21 1.32

8 PMR Compressor2 34.7 56 26 5.00 0.31 7.15 0.44 21.21 1.32

9 Cooler for Comp.1 26.5 46 22 5.00 0.39 21.21 1.67 21.21 1.67

10 Cooler for Comp.2 26.5 46 22 5.00 0.39 5.76 0.45 31.11 2.46

11 Cooler1 26.5 46 22 5.00 0.39 21.21 1.67 21.21 1.67

12 PMR Receiver 26.5 44 22 5.00 0.38 5.76 0.43 32.66 2.47

13 Heat Exchanger1 26.5 52 22 5.00 0.45 1.89 0.17 11.49 1.03

14 Heat Exchanger2 26.5 52 22 5.00 0.45 1.89 0.17 10.10 0.90

15 Expansion Valve1 26.5 46 16 5.00 0.54 1.89 0.21 12.24 1.33

16 Expansion Valve2 26.5 54 24 5.00 0.42 1.89 0.16 12.24 1.04

17 MR Phase Seperator 20.2 44 16 5.00 0.68 23.43 3.19 142.86 19.43

18 Heat Exchanger3 20.2 52 22 5.00 0.58 10.13 1.18 10.10 1.18

19 Heat Exchanger4 20.2 52 22 5.00 0.58 10.13 1.18 10.10 1.18

20 Expansion Valve3 20.2 54 24 5.00 0.56 23.43 2.61 23.43 2.61

21 Expansion Valve4 20.2 54 24 5.00 0.56 10.13 1.13 10.10 1.12

22MR Compressor Suction

Drum20.2 54 22 5.00 0.61 10.13 1.23 10.10 1.23

23 MR Compressor 30.6 58 28 5.00 0.34 10.13 0.69 10.10 0.68

24Cooler for

MRCompressor 20.2 38 14 5.00 0.67 10.13 1.36 10.10 1.36

25 Cooler2 30.6 48 24 5.00 0.33 10.13 0.66 10.10 0.66

Option 2 Option 3Base Option

39


Layout Optimization

Comparison of Integrated Inherent Safety Index (I2SI):

Comparison Results

• I2SI values are generally higher for the equipment in Option 3

compared to the other two.

• Option 3 has the largest extent applicability of inherent safety.

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Layout Optimization

Comparison of Cost Index:

Cost of Loss

No. Module Base Option($) Option 2($) Option 3($)

01 GT Module 5.09E+10 4.60E+10 4.60E+10

02 PMR Module 1 9.80E+10 9.22E+10 8.96E+10

03 PMR Module 2 7.60E+10 7.31E+10 6.79E+10

04 MR Module 1.24E+11 1.21E+11 1.13E+11

Total saving 1.65E+10 1.62E+10

Comparison Results

• Option 3 has best cost-effective performance compared to the others.

41


Layout Optimization

Comparison of Cost Index:

Base Option Option 2 Option 3

No. Module Cost of

Conventional

Safety (1000$)

Cost of Inhernt

Safety (1000$)

Cost Saving

(1000$)

Cost of Inhernet

Safety (1000$)

Cost Saving

(1000$)

01 GT Module 872 428 444 428 444

02 PMR Module 1 1250 960 290 762 488

03 PMR Module 2 1120 1780 -660 872 248

04 MR Module 1670 3350 -1680 2250 -580

Total saving -1606 Total Saving 600

Comparison Results

• Option 3 has best cost-effective performance compared to the others.

42


Conclusion

Risk-based Tool Part I:

• Dynamic hazard identification methodology is presented

• Generic model is developed

• Accommodate information update and realize real-time hazard

identification

Risk –based Tool Part II:

• Perform layout optimization using inherent safety method

• Safety measures and modules segregation can effectively prevent

hazard escalation

• Inherent safer design makes plant inherently safer and have better

cost-performance

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Future Work

• Integrate updating mechanisms into a Bayesian network

• Adopt more previous accident cases to extract historical data for

updating conditional probability tables.

• Conduct probability analysis and consequence

• Account for the impact of environmental forces on FLNG layouts.

• Further study the feasibility of the proposed FLNG topside layout

• compared to other existing naval architectures.

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Contributions

• Xin, P., Khan, F., & Ahmed, S. (2016). Dynamic Hazard Identification and

Scenario Mapping Using Bayesian Network. Paper under review of Process

Safety and Environmental Protection.

• Xin, P., Khan, F., & Ahmed, S. (2015). Layout Optimization of a Floating

Liquefied Natural Gas Facility Using Inherent Safety Principles. Paper

accepted at Journal of Offshore Mechanics and Arctic Engineering.

• Xin, P., Ahmed S., Khan, F., (2015). Inherent safety aspects for layout

design of a floating LNG facility. International Conference on Ocean,

Offshore, and Arctic Engineering (OMAE), St John’s, ASME.

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RISK-BASED DESIGN TOOLS FOR PROCESS FACILITIES · 2016. 10. 18. · Dynamic HAZID Model • Step 1:...

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