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1 Introduction........................................................................................................32 Summary.............................................................................................................3

2.1 Purpose..........................................................................................................32.2 Definition of Standard and Normal Conditions...............................................32.3 References.....................................................................................................32.4 Assumptions..................................................................................................42.5 Calculation Basis...........................................................................................42.6 Results and Conclusions................................................................................5

2.6.1 Backpressure.................................................................................................................52.6.2 Mach No. & Rho V2.......................................................................................................62.6.3 NOISE.............................................................................................................................. 6

3 LP Flare...............................................................................................................63.1 LP Flare Sources...........................................................................................63.2 LP Flare Network...........................................................................................73.3 LP Flare Relief Loads & Relief Gas Composition..........................................8

3.3.1 1st Stage Separator (V-1010 / 1020)...............................................................................83.3.2 2ND Stage Separator (V-1110 / 1120)..............................................................................83.3.3 Dehydrator (V-1510 / 1520) & Desalter (V-1610 / 1620)................................................93.3.4 Produced Water Treatment Package (AQ-4210)...........................................................93.3.5 Fuel Gas Treatment Package (AQ-6020).....................................................................103.3.6 Power Plant Fuel Gas Conditioning Package (AQ-7501).............................................10

3.4 LP Flare Purge.............................................................................................103.5 LP Flare Knock Out Drum, V-6205..............................................................113.6 LP Flare Stack (Smokeless Flaring).............................................................113.7 LP Flare Tip.................................................................................................11

4 LP Flare Scenarios...........................................................................................114.1 Scenario 1....................................................................................................124.2 Scenario 2....................................................................................................124.3 Scenario 3....................................................................................................134.4 Scenario 4....................................................................................................134.5 Scenario 5....................................................................................................144.6 Scenario 6....................................................................................................144.7 Scenario 7....................................................................................................154.8 Scenario 8....................................................................................................154.9 Scenario 9....................................................................................................164.10 Scenario 10...............................................................................................164.11 Scenario 11...............................................................................................17

5 Relief Load In Various Scenarios...................................................................176 Basis For Aspen Flare System Analyzer Study............................................187 LP Flare Design Criteria..................................................................................18

7.1 Header and Tailpipe.....................................................................................187.2 Noise Limitations..........................................................................................18

8 Recommendations...........................................................................................18

1 INTRODUCTION

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The LP Flare Network is an important part of FCP as it ensures the safe disposal of hydrocarbon releases from various pressurized sources. The 1st Stage and 2nd Stage separators of both trains are continuously relieving to LP flare header to maintain separator pressure. The following equipment / packages are also connected to the LP flare system for relief gas disposal: desalters, dehydrators, crude heater packages, fuel gas package, power plant fuel gas conditioning and produced water treatment packages.

The LP Flare source releases are estimated considering that each FCP Train is operating at the design production rate of 55000 bpd. Calculations produced in this document have been determined using Aspen Flare System Analyzer Version 7.3.

Once the various operating and relief scenarios that could occur are defined and the relief rates, venting rates and fluid properties are input into the flare system model, Aspen Flare System Analyzer performs numerous iterative calculations to size the LP flare network. Piping information i.e. layout, pipe lengths and fittings data are taken from piping isometrics in order to build the model.

2 SUMMARY

2.1 Purpose

The purpose of this calculation is to identify relief scenarios and determine the relief loads directed to the LP flare system and to select the line sizes in the flare system.

2.2 Definition of Standard and Normal Conditions

The standard and normal conditions for volumetric measurement of gases and liquids are defined at pressure and temperature of:

Standard = 1.013 Bara and 15.6°C.Normal = 1.013 Bara and 0°C.

2.3 References

Sr No Documents Attachment No of Pages

1 Extract of PSV Datasheet sizing Doc No. : P10-1033-P-DS-0003 Rev D2 (For Process Trains)

Attachment-A 4

2 1st Stage Separator – Total Flaring HYSYS stream summary

Attachment-B 2

3 1st Stage Separator – Blocked outlet HYSYS stream summary

Attachment-C 2

4 1st Stage Separator – Fire Case HYSYS stream summary

Attachment-D 2

5 1st Stage & 2nd Stage Separator - Blowdown Results

Attachment-E 4

6 2nd Stage Separator – Total Flaring HYSYS stream summary

Attachment-F 2

7 2nd Stage Separator gas flow during 1st Stage separator blocked outlet - HYSYS stream

Attachment-G 2

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Sr No Documents Attachment No of Pages

summary8 2nd Stage Separator- Gas blowby from 1st Stage

separator - HYSYS stream summaryAttachment-H 2

9 2nd Stage Separator – Fire Case HYSYS stream summary

Attachment-I 2

10 Dehydrator – Fire Case HYSYS stream summary

Attachment-J 2

11 Desalter – Fire Case HYSYS stream summary Attachment-K 2

12 PW Treatment Package- PSV Data Attachment-L 2

13 Fuel Gas Package- PSV & BDV Data Attachment-M 3

14 Power Plant Fuel Gas Conditioning Package- PSV & BDV Data

Attachment-N 3

15 Extract of Calculation for LP Flare KO Drum, Doc No.: P10-1033-P-CA-0146

Attachment-O 1

16 Flare package data from Flare Industries Attachment-P 2

17 Purge gas calculation Attachment-Q 1

18 Fuel Gas Package H&M Balance Attachment-R 2

19 P&ID’s Attachment-S 17

20 Piping Isometrics Attachment-T 8121 Pressure/flow summary (Results for scenarios 1-11) Attachment-U 11

2.4 Assumptions

1. Any operational contingency on one train will not affect the operation of other train.

2. Pipe lengths and fittings for the Fuel Gas Conditioning Package AQ-7501 and the Produced Water Treatment Package AQ-4210 are assumed.

3. Thermal relief from piping and pig receivers are not considered in this calculation as flow rates are insignificant for this relief contingency.

4. The relief case for the Produced Water Package AQ-4210 is control valve failure based on nitrogen flow. This flow data is currently not available. However, as this flow is limited by an RO and insignificant relative to the governing case for the LP flare, the available data for the thermal relief case given in attachment L is used in the calculations.

2.5 Calculation Basis

1. Various relief loads to LP flare network is considering that both crude processing trains are operating at 55,000 bpd (Design Flow).

2. PSV rated flow is used as the relief load for all cases except fire.

3. For fire case, the required flow of relief valve is used as the relief load even if the governing case is the fire case as there are other mitigating devices in place to reduce the relief load e.g. blowdown and active fire protection. The fire case relief loads also do not govern the flare header sizing in this plant.

4. API Fire circle (of 232 m2) is considered to identify the number of equipment in fire zone.

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5. LP flare relief load for fire case scenario of any of these three equipments (2nd stage separator, desalter & dehydrator) is the same. As fire circle will cover all three equipments 2nd stage separator, desalter & dehydrator of the particular train.

6. During operational contingency on one train, it is considered that the feed to the fuel gas package AQ-6020, will be at normal user flow rate demand (i.e., 2 Crude heaters + LP & ATM purge flows + Power Plant Fuel Gas Conditioning Package=2x1591+3x80+3x55+7964=11551 kg/h) from the other normal operating train. Otherwise, the fuel gas package will be withdrawing equally from the 1st stage separators of trains 1 and 2 and the remaining gas is flared off.

7. During a fire scenario, the relief loads considered are for equipment located in the fire zone and the blowdown rates are from equipment outside the fire zone.

8. In the case of multiple working PSVs, the total relief load is distributed equally to the operating PSVs.

9. In normal operation, fuel gas is continuously purged at 3 locations into the flare header ends to prevent burn back in the flare tip.

10. For the determination of maximum backpressures for multiple PSVs, the farthest working PSVs from the flare stack are assumed to be relieving.

2.6 Results and Conclusions

Aspen Flare System Analyzer simulations are carried out for all scenarios & results are evaluated against the design criteria.

2.6.1 BACKPRESSURE

Maximum back pressure for all scenarios (See attachment-U) is tabulated below.Scenarios Maximum Back

Pressure, bargLocation PCV / Relief

Valve

Scenario 1 0.24 Train 1- 2nd Stage Separator, V-1110 PCV-1110Scenario 2 Note 2 Note 2 Note-2Scenario 3 1.37 Train 1- 2nd Stage Separator, V-1110 PSV-1110CScenario 4 1.40 Train 2- 2nd Stage Separator, V-1110 PSV-1120CScenario 5 1.14 Train 1- Dehydrator, V-1510 PSV-1510Scenario 6 1.16 Train 2- Dehydrator, V-1520 PSV-1520Scenario 7 0.40 Train 1- 1st Stage Separator, V-1010 PSV-1010 CScenario 8 0.39 Train 2- 1st Stage Separator, V-1020 PSV-1020 CScenario 9 1.79 Fuel Gas Package, AQ-6020 PSV-6000 A/BScenario 10 0.34 Power Plant Fuel Gas Conditioning

Package, AQ-7501PSV-6027/28

Scenario 11 0.15 AQ-4210, IGF PSV-4220/4221

Notes:1- Maximum back pressure is observed at downstream of PSV-6000 A/B.2- In scenario 2 (Total Blowdown), all BDV’s will be operating and BDV’s operation is

independent of back pressure.3- In scenarios 3 and 4, the maximum back pressures slightly exceed the allowable 30%

back pressure, set in the simulation. However, as balanced bellows PSVs are used on 2nd

stage separators and the rated flow is 30% higher than the required flow, there is no concern.

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2.6.2 MACH NO. & RHO V2

In all scenarios, Mach No is significantly lower than 0.6 in all flare headers and sub-headers as well as Mach No. is lower than 0.5 downstream of all control valves (See Attachment U).

In all scenarios, Rho V2 is significantly lower than 200000 kg/m/s2, therefore is no concern (See Attachment-U).

2.6.3 NOISE

In all scenarios noise is significantly lower than 85 dB (A) thus there are no noise issues (See Attachment-U).

3 LP FLARE

3.1 LP Flare Sources

LP Flare sources are tabulated below

Source Name PCV / BDV / Relief Valve

V-1010 Train 1, 1st Stage Separator PCV-1011, BDV-1010, PSV-1010 A/B/C

V-1110 Train 1, 2nd Stage Separator PCV-1110, BDV-1110, PSV-1110 A/B/C

V-1510 Train 1, Dehydrator PSV-1510

V-1610 Train 1, Desalter PSV-1610

AQ-1111 Train 1, Crude Heater (Note 1) TSV-11101

V-1020 Train 2, 1st Stage Separator PCV-1020, BDV-1020, PSV-1020 A/B

V-1120 Train 2, 2nd Stage Separator PCV-1120, BDV-1120, PSV-1120 A/B

V-1520 Train 2, Dehydrator PSV-1520

V-1620 Train 2, Desalter PSV-1620

AQ-1112 Train 2, Crude Heater (Note 1) TSV-11201

AQ-6020 Fuel Gas Package (Note 2) PSV-6000 A/B, BDV-6001, BDV-6010

AQ-7501 Power Plant Fuel Gas Conditioning Package (Note 2)

PSV-6027/28, BDV-6001, BDV-6002

AQ-4210 Produced Water Treatment Package

PSV-4210/4211, PSV-4220/4221

Note 1: Source modeled in Flare-Net but as this is a thermal relief case it is ignored in the simulations.

Note 2: Only the governing and blowdown sources that are modeled in Flare-Net are given here.

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3.2 LP Flare Network

The LP flare network model schematic is shown below.

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3.3 LP Flare Relief Loads & Relief Gas Composition

The LP flare sources have different relief loads in accordance with the overall relief scenario. The relief gas composition is dependent on the relieving scenario.

3.3.1 1ST STAGE SEPARATOR (V-1010 / 1020)

PCV / BDV / Relief Valve

PCV-1011 /1021

PSV-1010 A/B/C / 1020

A/B/C

PSV-1010 A/B/C / 1020 A /

B /C

BDV-1010 / 1020

Scenario Total Flaring Blocked outlet Fire Adiabatic Blowdown

Reference Attachment-B Attachment-A Attachment-A Attachment-E

Relief load, kg/h 36668.7 30713* 10637 4559Pressure, barg 9.9 19.8 21.8 10.3Temperature, oC 65.8 66.0 174.3 66M.W. 24.2 22.8 34.8 24.2Composition Attachment-B Attachment-C Attachment-D Attachment-B

For adiabatic blowdown, composition is considered similar to total flaring case. *Required flow given, the rated flow of 33654 kg/h for two operating PSVs is used in calculations.

3.3.2 2ND STAGE SEPARATOR (V-1110 / 1120)


PCV-1011 /1021

PCV-1011 /1021 PSV-1110 A/B/C / 1120 A/B/C

PSV-1010 A/B/C / 1020

A / B /CScenario Total Flaring During 1st Stage

Blocked outletGas Blowby Fire

Reference Attachment-F Attachment-G Attachment-A Attachment-A

Relief load, kg/h 10545.9 12921 55556 8813

Pressure, barg 2.4 2.4 4.9 5.6Temperature, oC 104.1 104.6 105.0 141.7M.W. 38.3 42.6 25.6 37.8Composition Attachment-F Attachment-G Attachment-H Attachment-I

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2nd Stage Separator (V-1110 / 1120) During Blowdown


BDV-1110 / 1120

BDV-1110 / 1120

Scenario Adiabatic Blowdown

Fire Case Blowdown

Reference Attachment-E Attachment-E

Relief load, kg/h 4354 6207

Pressure, barg 2.8 4.5Temperature, oC 105 105M.W. 38.3 38.3Composition Attachment-F Attachment-F

For adiabatic & fire blowdown, composition is considered similar to total flaring case.

3.3.3 DEHYDRATOR (V-1510 / 1520) & DESALTER (V-1610 / 1620)

PCV / BDV / Relief Valve PSV-1510 / 1520 PSV-1610 / 1620Scenario Fire FireReference Attachment-A Attachment-ARelief load, kg/h 15993 15991Pressure, barg 20.5 20.5Temperature, oC 199.3 199.3M.W. 34.7 34.7Composition Attachment-J Attachment-K

3.3.4 PRODUCED WATER TREATMENT PACKAGE (AQ-4210)

PCV / BDV / Relief Valve PSV-4210 / 4211 PSV-4220 / 4221Scenario Thermal Relief* Thermal Relief*

Reference Attachment-L Attachment-LRelief load, kg/h 650* 650*Pressure, barg 9.6 9.6Temperature, oC 70 70M.W. 24.2 24.2Composition Attachment-R Attachment-R

*Thermal relief load used in calculations in the absence of actual data for control valve failure case. See section 2.4.

3.3.5 FUEL GAS TREATMENT PACKAGE (AQ-6020)

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Fuel Gas Treatment Package (AQ-6020) relief load is 63000 Kg/hr for the governing case. The PSV rated flow is limited to this required flow by the upstream train 1 and 2 control valve Cvs and system hydraulics.

Equipment V-6000 V-6000 S-6000 A/B

PCV / BDV / Relief Valve PSV-6000A/B BDV-6000 BDV-6010

Scenario Control Valve Failure

Adiabatic Blowdown

Adiabatic Blowdown

Reference Attachment-M Attachment-M Attachment-M

Relief load, kg/h 63000 331.5 932.6Pressure, barg 15.1 8.6 8.0Temperature, oC 60 60 75M.W. 24.2 24.2 24.2Composition Attachment-M&R Attachment-M&R Attachment-M&R

3.3.6 POWER PLANT FUEL GAS CONDITIONING PACKAGE (AQ-7501)

Power Plant Fuel Gas Conditioning Package (AQ-7501) relief load is 8381 kg/hr for the governing case.

Equipment E-6006 V-6005 E-6001


PSV-6027 / 6028

BDV-6002 BDV-6001

Scenario Tube Rupture Adiabatic Blowdown

Adiabatic Blowdown

Reference Attachment-N Attachment-N Attachment-N

Relief load, kg/h 8381* 705 1596Pressure, barg 8.3 21.6 20.5Temperature, oC 32.2 10.0 10.0M.W. 24.0 24.0 24.0Composition Attachment-N Attachment-N Attachment-N

*Required flow is used as the relief rate is limited by the supply of gas to this package.

3.4 LP Flare Purge

LP flare network is purged continuously with fuel gas through three locations (Train1 flare header, Train 2 flare header and fuel gas package, AQ-6020). Fuel gas purging requirement (for burnback prevention) is based on Flare Industries values and velocity criteria are adjusted to match the flow requirement. Purge gas flow rates are estimated based on a velocity of 0.092 m/s at flare tip.

During loss of fuel gas supply or during startup/shutdown, LP flare network is continuously purged with nitrogen through two locations (Train 1 Flare header, Train 2 Flare header). N2

purging requirement (for air-ingress prevention) is based on API velocity criteria (0.006-0.012

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m/sec). Velocity of 0.012 m/sec is used for calculation and this is in close agreement with Flare Industries values. Refer to Attachment-Q for purge gas calculation.

3.5 LP Flare Knock Out Drum, V-6205

Calculated pressure drop across the LP flare KOD is approximately 10 mbar at the rated flow of 94400 kg/h. However, the actual pressure drop across the drum is likely to be higher because of the inlet device and sump pump obstruction to flow path. (Refer to Attachment-O, Calculation for LP Flare KO Drum P10-1033-P-CA-0146).

3.6 LP Flare Stack (Smokeless Flaring)

The LP flare stack assembly consists of a 36 inch inner flare gas riser and a 78 inch outer pipe. The dilution air is blown through the annulus between the riser and the outer pipe. The stack height is 45.7 m from ground level (see Attachment-P, LP Flare Package data from Flare Industries).

3.7 LP Flare Tip

The Flare Tip contains a dynamic seal. Its pressure drop is 25.77 mbar at the design flow (see Attachment-P, LP Flare package data from Flare Industries).

4 LP FLARE SCENARIOS

The following 11 scenarios are identified for the LP flare calculations. An individual scenario is selected to have maximum relief load in different parts of LP flare system or simultaneous maximum load in different area.

Various Scenarios are listed below:Scenario 1 Total gas flaring Train 1 & 2Scenario 2 Total Facility BlowdownScenario 3 2nd Stage Separator gas blowby, Train 1Scenario 4 2nd Stage Separator gas blowby, Train 2Scenario 5 Fire Case Train-1Scenario 6 Fire Case Train-2Scenario 7 Blocked outlet 1st Stage separator, Train-1Scenario 8 Blocked outlet 1st Stage separator, Train-2Scenario 9 FG Package control valve failureScenario 10 Power Plant Fuel Gas Conditioning PackageScenario 11 PWT Package control valve failure

4.1 Scenario 1

Scenario 1 is maximum flaring of associated gas from both trains and each train is operating at design flowrate of 55000 bopd. Relief Loads from various sources are tabulated below.

Source Name PCV / BDV / Mass Relief Rate Relief Scenario

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Relief Valve (Gas), kg/h

V-1010 Train-1, 1st Stage Separator PCV-1011 36668.7 Total Flaring

V-1110 Train-1, 2nd Stage Separator PCV-1110 10545.9 Total Flaring

V-1020 Train-2, 1st Stage Separator PCV-1021 36668.7 Total Flaring


Total LP Flare Load 94429.3

4.2 Scenario 2

Scenario 2 is considering the total facility Blowdown e.g. during ESD. Relief Loads from various sources are tabulated below.


Mass Relief Rate (Gas), kg/h

Relief Scenario

V-1010 Train-1, 1st Stage Separator BDV-1010 4559 Adiabatic Blowdown

V-1110 Train-1, 2nd Stage Separator BDV-1110 4354 Adiabatic Blowdown



AQ-6020 Fuel Gas Package BDV-6000 331.5 Adiabatic Blowdown


AQ-7501Power Plant Fuel Gas Conditioning Package

BDV-6001 1596 Adiabatic Blowdown




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4.3 Scenario 3

Scenario 3 is considering the Gas blowby from train 1, 2nd Stage Separator and gas from train 2 is under normal flaring. Relief Loads from various sources is tabulated below.



Relief Scenario

V-1110 Train-1, 2nd Stage Separator PSV-1110 B 27778.0 Gas Blowby

V-1110 Train-1, 2nd Stage Separator PSV-1110 C 27778.0 Gas Blowby

V-1020 Train-2, 1st Stage Separator PCV-1021 25117.7Total Flaring less Fuel Gas Consumption of 11551 kg/h


Purge Gas Flow 240.0


4.4 Scenario 4

Scenario 4 is considering the Gas blowby from train 2, 2nd Stage Separator and gas from train 1 is under normal flaring. Relief Loads from various sources is tabulated below.



Relief Scenario

V-1010 Train-1, 1st Stage Separator PCV-1011 25117.7Total Flaring less Fuel Gas Consumption of 11551 kg/h


V-1120 Train-2, 2nd Stage Separator PSV-1120 B 27778.0 Gas Blowby

V-1120 Train-2, 2nd Stage Separator PSV-1120 C 27778.0 Gas Blowby



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4.5 Scenario 5

Scenario 5 is considering Train 1, 2nd stage separator is under fire and depressurized. Fire circle is spreading over desalter and dehydrator.1st stage separator is depressurized adiabatically. Train 2, Fuel gas Package & Power Plant Fuel Gas Conditioning Package is under adiabatic blowdown. Relief Loads from various sources is tabulated below.



Relief Scenario


V-1110Train-1, 2nd Stage Separator

BDV-1110 6207 Fire Case Blowdown

V-1510 Train-1, Dehydrator PSV-1510 15993 Fire Case

V-1610 Train-1, Desalter PSV-1610 15991 Fire Case


V-1120Train-2, 2nd Stage Separator









4.6 Scenario 6

Scenario 6 is considering Train 2, 2nd stage separator is under fire and depressurized. Fire circle is spreading over desalter and dehydrator.1st stage separator is depressurized adiabatically. Train 1, Fuel gas Package & Power Plant Fuel Gas Conditioning Package is under adiabatic blowdown. Relief Loads from various sources is tabulated below.



Relief Scenario




V-1120 Train-2, 2nd Stage Separator BDV-1120 6207 Fire Case Blowdown

V-1520 Train-2, Dehydrator PSV-1510 15993 Fire Case

V-1620 Train-2, Desalter PSV-1610 15991 Fire Case








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4.7 Scenario 7

Scenario 7 is considering that Train 1, 1st stage separator is under relieving under blocked outlet condition and Train 2 is normal flaring. Relief Loads from various sources is tabulated below.



Relief Scenario

V-1010 Train-1, 1st Stage Separator PSV-1010 C 16827 Blocked Outlet

V-1010 Train-1, 1st Stage Separator PSV-1010 B 16827 Blocked Outlet

V-1110 Train-1, 2nd Stage Separator PCV-1110 12921Blocked Outlet of 1st Stage separator

V-1020 Train-2, 1st Stage Separator PCV-1021 25118Total Flaring less Fuel Gas Consumption of 11551 kg/h




4.8 Scenario 8

Scenario 8 is considering that Train 2, 1st stage separator is relieving under blocked outlet condition and Train 1 is total flaring. Relief Loads from various sources is tabulated below.



Relief Scenario

V-1010 Train-1, 1st Stage Separator PCV-1011 25118Total Flaring less Fuel Gas Consumption of 11551 kg/h


V-1020 Train-2, 1st Stage Separator PSV-1020 C 16827 Blocked Outlet

V-1020 Train-2, 1st Stage Separator PSV-1020 B 16827 Blocked Outlet

V-1120 Train-2, 2nd Stage Separator PCV-1120 12921Blocked Outlet of 1st stageseparator

Purge Gas Flow 240


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4.9 Scenario 9

In this scenario, the 1st Stage Separator fuel gas PCVs of both trains are wide open and the maximum flow through each PCV, assuming a hydraulically balanced system, is 63000 kg/h divided by 2 i.e. 31500 kg/h. Thus, the flare PCV flow from each 1st stage separator is equal to the total flaring load of 36668.7 kg/h less 31500 which equals 5168.7 kg/h. The 2nd stage separator flare PCV is maintaining its position and relieving 10545.9 kg/h. Relief loads for this scenario are given below.


Mass Relief Rate (Gas), Kg/Hr

Relief Scenario

V-1010 Train-1, 1st Stage Separator PCV-1011 5168.71st Stage Separator fuel gas PCVs


V-1020 Train-2, 1st Stage Separator PCV-1021 5168.71st Stage Separator fuel gas PCVs


AQ-6020 Fuel Gas PackagePSV-6000 A/B

63000 Control Valve Failure


4.10 Scenario 10

Scenario 10 is considering normal train operation with tube rupture occurring in the chiller exchanger in the Power Plant Fuel Gas Conditioning Package. Relief loads for this scenario are given below.



Relief Scenario

V-1010 Train-1, 1st Stage Separator PCV-1011 30893Total Flaring less half of 11551 kg/h





PSV-6027/28 8381 Tube Rupture

Purge Gas Flow 240


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4.11 Scenario 11

Scenario 11 is considering normal train operation with the PWT Package fuel gas padding valve failing open. Relief loads for this scenario are given below.



Relief Scenario



V-1020 Train-2, 1st Stage Separator PSV-1010 A 30893Total Flaring less half of 11551 kg/h

V-1120 Train-2, 2nd Stage Separator BDV-1120 10545.9 Total Flaring

AQ-4210 PW Treatment PackagePSV-4210/11 or PSV-4220/21

650 Control Valve Failure

Purge Gas Flow 240


5 RELIEF LOAD IN VARIOUS SCENARIOS

LP flare relief load for various scenarios is tabulated below

Scenarios Relief Load , kg/h Relief Load, MMscfdScenario 1 94429.3 71.87Scenario 2 21391.1 15.07Scenario 3 91459.7 70.04Scenario 4 91459.7 70.04Scenario 5 55228.1 34.79Scenario 6 55228.1 34.79Scenario 7 82478.7 62.97Scenario 8 82478.7 62.97Scenario 9 94429.3 71.87Scenario 10 91498.8 69.64Scenario 11 83768.3 63.02

Scenario 1 and 9 are the governing relief load for LP flare system.

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6 BASIS FOR ASPEN FLARE SYSTEM ANALYZER STUDY

1. Calculation is carried out in the Rating Mode.

2. Pipe roughness used is 0.050 mm.

3. Calculation options assumed are as follows:

VLE Method = Peng Robinson;

Enthalpy Method = Lee Kessler;

Pressure Drop Method = Beggs and Brill (Homogenous)

Friction Factor Method = Chen

7 LP FLARE DESIGN CRITERIA

7.1 Header and Tailpipe

Pipe Work Parameter Criteria Reference

Main Header / Sub header Mach No. <0.6 Process Design Philosophy, P10-1033-P-RE-0003

7.2 Noise Limitations

A. For emergency conditions the noise level not to exceed 115 dB(A).B. For normal operation noise levels not to exceed 85 dB(A).

8 RECOMMENDATIONS

The Power Plant Fuel Gas Conditioning Package (AQ-7501) PSV`s are currently conventional types. From the Flarenet simulations it is recommended to select balance bellow PSV`s to handle higher back pressures. It is also recommended for Petronas to revise the Flarenet model with final PSV relief loads and back pressures once the Power Plant Fuel Gas Conditioning Package vendor has finalized the design.

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lp flare network calculation rev- e0

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