Process Department

COMPARATIVE STUDY OF THE USE OF VISUAL FLOW, INPLANT AND OTHER SSE-06 COMPARATIVE STUDY OF THE USE OF VISUAL FLOW, INPLANT AND OTHER SIMULATORS IN THE RELIEF SYSTEM DESIGN Prepared by: Pedro Ceballos Revised by: Edgar Alfonso / Carmelo Trezza / María Pereira / Fernando Azuaje Invensys User Group Series, Houston, October 15-16 Copyright © 2012. Inelectra SACA.- All rights reserved

Content Relief Systems Relief System Components Relief System Hydraulic Evaluations DA-1/ DA-2/ VDU Relief System Hydraulic Evaluation Comparison of Simulators Conclusions

Relief Systems Definition: Standards Applicable to Relief Systems: Installing a pressure relief device, lines and means for transport and disposal of the relief fluid in gaseous phase, liquid or both. It is used when the presence of liquid, toxic properties or other factors would make it dangerous to discharge into the atmosphere Standards Applicable to Relief Systems: API 520 I. Sizing, Selection, and Installation of Pressure-Relieving Devices in Refineries. Part I—Sizing and Selection API 520 II. Sizing, Selection, and Installation of Pressure-Relieving Devices in Refineries. Part II—Installation API 521. Pressure-relieving and Depressuring Systems API 526. Flanged Steel Pressure Relief Valves API 537. Flare Details for General Refinery and Petrochemical Service API 576. Inspection of Pressure-relieving Devices

Relief System Components Relief Valves Flare Discharge Lines Protected Equipments Subheaders Header KnockOut Drum KnockOut Drum Pumps

Relief System Hydraulic Evaluations P1= ? psig (Backpressure) P2= 0 psig Criteria to define the relief valve type: Relief Valve (Set pressure) DPtip= 3 psig BP Backpressure (psig) SP Set Pressure (psig) (%) = Flare Conventional: BP/SP<10% Balanced: 10%<BP/SP<30% Pilot: 30%<BP/SP<75% DPsello= 2 psig KnockOut Drum

DA-1/ DA-2/ VDU Relief System Hydraulic Evaluation Description: Project: Deep Conversion Location: Puerto La Cruz Refinery Engineering: Detail Units Involved: DA-1/DA-2 (Atmospheric Distillation Units) VDU (Vacio Unit) Flare Type: Ground Flare Darwin LNG; Australia

DA-1/ DA-2/ VDU Relief System Hydraulic Evaluation Main Objective: * Validate the results obtained during the basic engineering of hydraulic calculations associated with the main header of Ground Flare Relief System and DA-1/DA-2/VDU referred to in the Deep Conversion Project of Puerto La Cruz. Secondary Objective : * Compare the use, advantages and disadvantages of simulators available in the Company (INELECTRA) for Relief Systems Analysis (VISUAL FLOW, INPLANT, Aspen Flare and Superchems).

DA-1/ DA-2/ VDU Relief System Hydraulic Evaluation Relief System Design : Main Contingency: General Electric Power Failure Total Relief Load: 782392 lb/h Size Head: 42’’ Equipment Involved DA-1: Atmospheric Tower DA-2: Atmospheric Tower VDU: Vacuum Tower Design Basis: * Pressure of 10 psi at Ground Flare. In the General Electric Power Failure DA-1, DA-2 and VDU discharge simultaneously. Maximum speed (Mach): Discharge Line: 0.75 / Header-SubHeader: 0.50. Backpressure criteria: Conventional: 10% / Balanced: 30% / Pilot: 75%.

DA-1/ DA-2/ VDU Relief System Hydraulic Evaluation Relief System Scheme: VDU TRAIN 1 & 2 42’’ DA-1 Ground Flare DA-2

DA-1/ DA-2/ VDU Relief System Hydraulic Evaluation VISUAL FLOW Simulation: VDU Towers DA-1 Tower DA-2 Tower

DA-1/ DA-2/ VDU Relief System Hydraulic Evaluation INPLANT Simulation VDU Towers DA-1 Tower DA-2 Tower

DA-1/ DA-2/ VDU Relief System Hydraulic Evaluation Aspen Flare Simulation DA-2 Tower DA-1 Tower VDU Towers

DA-1/ DA-2/ VDU Relief System Hydraulic Evaluation SuperChems Simulation

DA-1/ DA-2/ VDU Relief System Hydraulic Evaluation Results. Cooling Water Failure (DA-1 Tower) SIMULATOR PARAMETER PSV-04416A PSV-04416B PSV-04416C PSV-04416D PSV-04416E PSV-04416F SP=30psig SP=31.5psig BASIC ENG. (SUPERCHEMS) Outlet Line Mach Nro 0.191 Backpressure (psig) 21.9 Back P / Set P (%) 73.1 69.6 DETAIL ENG. (VISUAL FLOW) 0.216 0.214 0.313 15.0 15.3 14.7 14.6 49.9 48.6 46.6 46.5 Results. General Power Failure (DA-2 Tower) SIMULATOR PARAMETER PSV-05391-A PSV-05391-B PSV-05391-C SP= 30 psig SP= 31.5 psig BASIC ENG. (SUPERCHEMS) Outlet Line Mach Nro 0.169 Backpressure (psig) 21.5 Back P / Set P (%) 71.5 68.1 DETAIL ENG. (VISUAL FLOW) 0.192 15.4 15.7 51.3 48.8 49.8

DA-1/ DA-2/ VDU Relief System Hydraulic Evaluation Origin of differences (Basic Eng. – Detail Eng.) Header Inside Diameter 42’’: Basic Eng.: Detail Eng. (Piping Classs) 40’’ 41.188’’ Fittings (Basic Eng.): Elbow 90° 90 deg. 1 Weld. 90 deg angle Elbow 45° 45 deg. Standard (R/D=1), all types T branch Used as elbow. Standard, screwed T run Run through tee. Screwed K(12”)=1.247 Fittings (Detail Eng): Elbow 90° Long-Radius (R/D=1.5), all types Elbow 45° 45 deg. Long radius (R/D=1.5), all types T branch Used as elbow. Standard, flanged/welded T run Run through tee. Flanged/welded K(12”)=0.217

DA-1/ DA-2/ VDU Relief System Hydraulic Evaluation Results. Cooling Water Failure (DA-1 Tower) SIMULATOR PARAMETER PSV-04416A PSV-04416B PSV-04416C PSV-04416D PSV-04416E PSV-04416F SP=30psig SP=31.5psig VISUAL FLOW Outlet Line Mach Nro 0.216 0.214 0.313 Backpressure (psig) 15.0 15.3 14.7 14.6 Back P / Set P (%) 49.9 48.6 46.6 46.5 INPLANT 0.209 15.9 52.8 50.3 ASPEN FLARE 0.212 0.211 0.210 16.3 16.1 54.4 50.4 51.0 51.2 51.3 51.1 SUPERCHEMS 50.1 47.7

DA-1/ DA-2/ VDU Relief System Hydraulic Evaluation Results. General Power Failure (DA-2 Tower) SIMULATOR PARAMETER PSV-05391-A PSV-05391-B PSV-05391-C SP= 30 psig SP= 31.5 psig VISUAL FLOW Outlet Line Mach Nro 0.192 Backpressure (psig) 15.4 15.7 Back P / Set P (%) 51.3 48.8 49.8 INPLANT 0.185 16.2 16.1 54.1 51.0 ASPEN FLARE 0.186 16.3 54.3 51.9 51.7 SUPERCHEMS 0.187 15.8 52.6 50.1

Comparision of Simulators Mounting the Model: VISUAL FLOW INPLANT ASPEN FLARE SUPERCHEMS Allows change the method of thermodynamic YES NO Allows added viscosity experimental data. Easy to add components and uses them when performing the simulation on other computers Allows to create pseudocomponentes with PM>1000 Allowsto add over 50 pseudocomponentes in a line Allows to add pipes to the library Allows to copy valves and equipments Allows to enable and disable lines and equipments Ease of data entry

Comparision of Simulators Simulator Flexibility: VISUAL FLOW INPLANT ASPEN FLARE SUPERCHEMS Evaluation of the pressure drop at the entrance of the safety valve YES NO Can simulate various scenarios (contingencies) with a single run Sizing Relief Valves Sizing Relief Headers Allows isometric drawings Dynamic Evaluation of Fire Contingency Radiation Evaluation It takes into account energy losses to the environment

Comparision of Simulators Results Report: VISUAL FLOW INPLANT ASPEN FLARE SUPERCHEMS Getting quick results (duration of the run) YES NO Reports the pressure drop in each segment / fitting Calculation of relief temperature Easy to calculate backpressure on PSV

Comparision of Simulators General recommendations for use of simulators according to the case study Case Simulator Simulation of gas relief VISUALFLOWSuperchems Simulation of viscous liquid relief Inplant Simultaneous evaluation of several cases where contingency is involved one relief valve VISUALFLOW Aspen Flare Quick estimate of the backpressure INPLANT Evaluation of the pressure drop at the entrance to the relief valve VISUALFLOW Superchems Evaluation of Fire event when multiple loads are involved (dynamic simulation) Superchems Evaluation of heat loss to the environment Superchems, AspenFlare

Conclusions * The diameters established for the main header (42"), for DA-1 subheader (42") and DA-2 subheader (30") during basic engineering are according with the design basis. * It should verify that the fittings on the pipes do not create an excessive pressure drop avoid unnecessary overdesigns. * According to the system under study, each relief systems simulator offers particular advantages, among them are the INPLANT by the facilities in the model assembly and VISUAL FLOW for flexibility and good results.

Thanks for your attention!!