PowerPoint Presentation

CP512Y: Final Year Project Group Members:

Danial Said AbdatHariz Bin Mohamed YousufVikkramm S/O RavindrenContent PageProject Brief

Literature Review

Introduction of Equations

Verifying the Equations

Preliminary investigations

Our Software

The Scenario

The Analysis

Next PhaseProject Title: Conduct Quantitative Risk Assessment on a Chemical Store Alternate brief: This project will guide personnel with the use of a software that quantifies the extent of damages into figures which can be studied qualitatively. This will further allow them to generate a report similar to a sample that is provided with the software and hence enable them to strengthen their laboratory chemical safety management. (confirm with ms lee)

(explain what it does) like how it moves onto using a software then applying the values obtained into a sample analysis/reportFYP ObjectivesResearch on the model equations available to calculate: Blast overpressure Thermal radiation intensity

Implement the equations into a software to enable users to easily obtain the calculated data

Host a website which:Allows our software to be downloadContains detailed materials on useful definitions and informationSample analysis to guide them after acquiring their results-the equations are long and complex, calculating it manually for numerous values would be extremely tediousLiterature ReviewWhat is Quantitative Risk Assessment (QRA)?

Structured and Systematic Approach to identifying risks associated with hazards

Provides information on risk profile of the operation

Pre-requisite for design and operation of plantAlso known as QRA..Quantitative Risk Assessment is a structured and systematic approach to identifying risks associated to the hazards present. It provides more information on the risk profile of the operation and location of activity taking place. It is used as a basis for decision-making in the design and operation of a plant

Qualitative Risk Assessment: Non-numerical values to form a 3x3 matrix to describe severity of hazards e.g Severity (Low, medium, high) vs Probability (Likely, unlikely, highly unlikely)

Quantitative Risk Assessment: Numerical values to quantify severity and probability of event occurring e.g fatalities per event and events per year

Qualitative vs Quantitative Risk AssessmentQualitative Risk Assessment gives us a non-numerical value to describe the severity of hazards (low, medium or high) and probability of hazards occurring (very unlikely, unlikely or rather unlikely) to form a 3X3 matrix to evaluate which category (low, medium or high risk) the event falls in. However, Quantitative Risk Assessment involves the quantification of the severity (fatalities per event) and probability of hazards(events per year) and multiplying the two to obtain the magnitude of the risk (fatalities per year). Even though Quantitative Risk Assessment is more objective compared to Qualitative Risk Assessment, it is more troublesome to obtain the values needed to calculate the magnitude of the risk. Hence, for some RA, there is no necessity for the RA to be objective and Qualitative RA may be a better option as it is formulated faster.

Importance of QRAWhy do we need Risk Assessment?

to prevent injury to employees and third parties

to not damage to the environment

to comply with regulatory bodies

to not incur financial losses

Key Definitions What is Thermal Radiation Intensity?

Electromagnetic radiation generated

Emitted by all matters with temperature above absolute zero

How is it emitted?

Direct result of fireball produced from explosion

Absorbed by exposed surfaces, resulting in damage e.g burns

Thermal radiation is the electromagnetic radiation generated due to the thermal motion of charged particles in matter. Thermal radiation is emitted by all matter as long as their temperature is above absolute zero.

It is a direct result of a fireball that may be produced by an explosion.The explosion produces a fireball which creates thermal radiation that strikes on exposed surfaces and is absorbed into the material, causing damage. Key Definitions What is Blast Overpressure?

High energy impulse noise from explosive detonations

Exposure can result in injuries to auditory, respiratory and gastrointestinal systems

Blast overpressure, also known as high energy impulse noise is a damaging outcome resulting from explosive detonations. Exposure to blast overpressure shock waves can result in injuries to the auditory, respiratory and gastrointestinal systems.

Where

ItA : Actual thermal radiation intensity (kW/m2)X : ParameterRt : Distance from fireball to the target (m)E : Heat Released (J)Fr : Fraction of heat radiatedD : Duration of fireballIntroduction of equations usedTaken to be 1.0 to obtain a conservative resultWhere

It : Unattenuated thermal radiation intensity (kW/m2)Rt : Distance from fireball to the target (m)Where

: atmospheric attenuationX : parameterIntroduction of equations usedWhere

M : Mass of chemical entering fireball (ton) : Theoretical Adiabatic Flash FractionMs : Mass of chemical in vessel (ton)Where

Et : Heat Released (J)H: Heat of combustion (J/ton)M: Mass of chemical (tons)

Where

D : Duration of fireball (s)M : Mass of chemical (ton)Where

P : Radiative Power (W)Fr : Fraction of heat radiatedAssumed to be 0.3Introduction of equations usedMarshall Model

Where

mTNT is the equivalent mass of TNT is the explosion efficiencym is the mass of fuel involved (kg)Hc is the energy of explosion of the gas (MJ/kg)ETNT is the energy of explosion of TNT (MJ/kg)Where

Ze is the scaled distance (m/kg1/3)r is the distance from center of explosion (m)

Where

Ps is the scaled overpressureWhere

Po is the peak overpressure (psi)Pa is the ambient pressure (psi)Introduction of equations usedVerifying the equations KeroseneMass of Chemical16.2 kgDensity of Chemical810 kg/m3Heat of Combustion of chemical43000 kJ/kgFraction of Heat Radiated0.3n, Empirical Explosion Efficiency0.05TNT Equivalent4.686 MJ/kgBefore we carried out the verification of the equations, several information of the chemical was required. All the values except for the mass of the chemical, were obtained from the internet.

Empirical explosion efficiency is used to estimate the number of factors such as incomplete mixing of air and combustible material or incomplete conversion of thermal energy to mechanical energy. Since the explosion efficiency is empirical with values ranging from 1% to 10%, the average value of 5% was used for our calculation.

As for the Fraction of heat radiated, several different formulas exist but are rather complex to apply, hence we used the given value of 0.3 Verifying the equationsThermal RadiationDistance to:Results(1) 4.0 kw/m258.55m(2) 12.5 kw/m233.70m(3) 37.5 kw/m219.80m(4) Max. Fireball Radius6.96m(5) Duration of Fireball0.96sBlast Overpressure (psi)Distance (m)5.012.712.029.341.053.790.584.11these are the values which we used to back calculate using our equationsNEED INTEXT CITATION?Verifying the equationsDistance (m)Calculated Blast Overpressure (psi)Actual Blast Overpressure (psi)12.715.405.029.341.762.053.790.901.084.110.570.5Blast Overpressure (psi)Calculated Distance (m)Actual Distance (m)5.013.3412.712.026.2529.341.048.9353.790.595.7184.11(left) we calculated the distance from the center of explosion using our blast overpressure equation and the given blast overpressure value(right) we then tried calculating the blast overpressure using the same equation but instead used the given distance from the center of explosionit can be seen that the values we obtained using our equation has some slight discrepancies (why??)Verifying the equationsThermal RadiationResultsCalculated Distance to:Actual Distance to:58.55m(1) 3.98 kw/m2(1) 4.0 kw/m233.70m(2) 12.44 kw/m2(2) 12.5 kw/m219.80m(3) 37.25 kw/m2(3) 37.5 kw/m2Thermal RadiationDistance to:Calculated ResultsActual Results(1) 4.0 kw/m258.37m58.55m(2) 12.5 kw/m233.62m33.70m(3) 37.5 kw/m219.74m19.80m(4) Max. Fireball Radius6.96m6.96m(5) Duration of Fireball0.96s0.96s(left) now, for the thermal radiation intensity, we calculated the distances at which radiations of 4, 12.5 and 37.5 kw/m2 are emitted respectively(right) then, we calculated the TRI emitted at certain distances from the center of explosionbased on the results shown in the tables, it can be deduced that our equation is rather accurate as the values we obtained are almost similar to those of the actual values. with that in mind, we moved on to investigate on the ways to make our prototypePreliminary InvestigationMicrosoft Excel Spreadsheet

Microsoft Excel with Visual Basics for Applications (VBA)Microsoft Excel SpreadsheetAble to simplify calculations which use long and complex equations

We have knowledge on using the excel spreadsheet

Very versatilenow let us take a look at the advantages and disadvantagesAdvantages:

Pre-input equations into spreadsheet that does not need to be changed by user

Layout that can be easily understood by user

Users are generally quite familiar with Microsoft ExcelMicrosoft Excel SpreadsheetMicrosoft Excel SpreadsheetDrawbacks:

Limited functionality of the excel spreadsheet when it is put into a website

Users must have basic knowledge of how excel works

can go 2 directions, 1 , is to put into a website, 2 , is to let users download the spreadsheet for their useMicrosoft Excel with VBAAllows the creation of a user-friendly application

Diverse and dynamic application

More aesthetic appeal

Can be uploaded onto a website for users to downloadMicrosoft Excel with VBAAdvantages:

Simple interface for users

Does not require users to have good excel knowledge

Allows us to incorporate the excel solver excel add-in into calculationsMicrosoft Excel with VBADrawbacks:

Coding knowledge is required

Very tedious and difficult to debugChosen: Microsoft Excel with VBAWhy?

Advantages of using VBA outweighs just using Microsoft Excel alone

Provides us with more options

Mainly due to:

Allows us to give the users a simple experience

Able to use the excel solver add-in without requiring additional steps

after evaluating the options, we decided to choose vba due to...explain simple experience. survey layout, not messyshortly, we will show you why VBA was chosen

Chosen: Microsoft Excel with VBA

Microsoft Excel with VBAWe researched and learnt about coding

With the use of coding, equations were input into VBA to calculate the values required

Several information were keyed in for the software to calculate the valuesFinally able to make use of the excel solver in a simpler way for usersOur Software

Our Software

Our Software

Our Software

Our SoftwareScenarioOur focus was on W318 as large quantities of ethanol were stored there

A worst case scenario was drafted based on our views

The usefulness of the results from the software is reflected in our analysis

ScenarioWhere did the incident occur? W318Who were the people present at the location at that time? A class of students and TSOWhat chemicals caused/contributed to the explosion? EthanolWhat was the quantity of the chemicals stated above in W318?100L of ethanol How did the chemical ignite? Electrical sparks ignited the ethanolWhy were electrical sparks present? Overloaded socket; too many electrical appliances using the same socket Possible consequence: Blast generated strong enough to damage the nearby LPG tank

-resulting in an excessively large amount of current being drawn from the main electrical socket-which might result in a bigger fire and even more damages to nearby infrastructure.

Scenario EthanolVolume of Chemical100LDensity of Chemical789.00 kg/m3Heat of Combustion of chemical29700 kJ/kgMass of Chemical0.0789 tonnesFraction of Heat Radiated0.3n, Empirical Explosion Efficiency0.05TNT Equivalent4.686 MJ/kgDemonstration!- Here is the relevant information we require to run our software-for the purpose of this calculation we set the empirical explosion efficiency to be 5% and the fraction of radiated to be 0.3.-with this, we shall proceed to a simple demonstration of our software with the above dataThe AnalysisWith the data obtained, we developed our own QRA report

To study the extent of damages that may come about from the worst case scenario

come here after software demonstrationThe Analysis Results Maximum Fireball Radius11.79mDuration of Fireball1.63s Blast Overpressure (psi)Distance from the centre of explosion (m)5.019.9852.039.3361.073.3110.5143.4013.127.6Thermal Radiation Intensity (kW/m2)Distance from the centre of explosion (m)4.083.212.547.937.528.237.327.6

-these are the results we obtained after using our software-We calculated the distances from the ethanol tank which would experience 0.5, 1, 2 and 5 psi blast overpressure and 4, 12.5 and 37.5kW/m2 thermal radiation intensity. These values were the standard values used by the Singapore Civil Defence Force in hazard analysis. -Taking into account the explosion, the next explosive object within the vicinity were the 12 LPG tanks located 27.6m from the ethanol tank. These LPG tanks were sources of fuel for the stalls at Food Court 1. The overpressure and thermal intensity that will be felt by the LPG tanks during the explosion were calculated to determine if the blast from the ethanol would cause the LPG tanks to explode.-27.6m is the distance between the ethanol tank and the nearby LPG tanks at FC1

The Analysis Hazard Contour37.5kW/m212.5kW/m24kW/m227.6m46.9m81.3m-from the distances obtained, we developed a hazard contour to allow us to identify the possible damages that may arise from the explosion

- Parts of W319 and parts of W315 walls be badly damaged- LPG tanks may get dented and the steel cage protecting the tanks may be damaged severely- Serious injuries to passers-by including some fatalities

- All glass windows at the sides of FC1 will shatter- Passers-by injured by flying window shards

- All Windows and glass panels in FC1 will shatter- Glass panels along the corridor outside FC1 will also shatter- People might get injured by flying debris

- All of W318 walls will collapse- Neighbouring workshops W317 and W319 will have severely damaged walls- All surrounding equipment and units would get severely damaged- Humans in the vicinity may die or the very least be severely injured due the effects

The Analysis Hazard Contour20.0m 27.6m 73.3m 39.3m -The Analysis Conclusion The explosion will result in a complete destruction of W318, along with its surrounding facilities and civilians

The LPG tanks: Badly dented and bruised Will not rupture Blast overpressure not strong enoughProtected from flying debris by steel cagesWill not ignite Thermal radiation intensity not high enough to cause auto-ignition Lack of ignition source from surroundings

-in our analysis document, we also included the current protective and preventive measures along with possible improvements that can be made to mitigate the chances of a chemical explosionMethodologyScenario summary

Detailed Scenario

CalculationsBlast Overpressure dataThermal Radiation Intensity data

Hazard ContourExtent of damages

Discussion

Current Protective and Preventive Measures

Improvements-from our sample analysis, we made it for the purpose that it can be used by others as a guide for them to generate their own analysis after obtaining the data aquired from our software.-explain usefulness of analysisThe timeline so far... Project BriefTemplate for QRAImprove on PrototypePrototype CreationSample QRAPreliminary InvestigationLiterature ReviewFindingEquationsDefinitions of TermsObjectives & ScopeVerification of Equationsif unsuccessfulCreate WebsiteGet Feedback on PrototypeFinalise PrototypeReport WritingEndsummarising, this is the timeline of what we have done so farNext phase of our projectObtain feedback and suggestions from TSOs and lecturers on our software

SoftwareMake changes and improvementsAdd in more features if required (from feedback)

WebsiteCreate a user-friendly websiteContain useful information and factsA place to download our software

Get approval from NEA/ relevant authorities

-HOPEFULLY be able to get NEA or the relevant authorities to check our software and website, get their approval and acknowledgment that what we have come out is legitQUESTIONS?Obstacle Faced (preliminary studies) (script)Equations were complex and long, so we decided to use microsoft excel

However, we could not carry out certain calculations for blast overpressure as the equation was very complex.

Took us some time to find a solution and we came upon excel solver.Obstacle Faced (preliminary studies) (script)Our calculation requires an additional plug-in that cannot be used in websites

Messy layout

Decided to use Visual Basics Applications (VBA)Obstacle Faced (script)- Direct calculations from website cannot be done due to the excel solver function

-VBA had to be used as the excel solver function was necessary for the calculations of blast overpressurepictures